Enhanced control channel in multicarrier wireless networks

ABSTRACT

A base station transmits downlink control information on a first carrier starting from the first symbol of a first subframe and provides first transmission format and scheduling information for first data packets to be transmitted on a first data channel of the first carrier. The base station transmits control message(s) configuring radio resources of a second control channel of a second carrier. The radio resources comprise one or more sets of resource blocks in a subset of subframes. The control message indicates a starting OFDM symbol in a subframe and a frequency allocation for said second control channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/535,530,filed Jun. 28, 2012, entitled “Control Channels in Multicarrier OFDMTransmission,” which claims the benefit of U.S. Provisional ApplicationNo. 61/503,625, filed Jul. 1, 2011, entitled “Control Channels inMulticarrier OFDM Transmission,” and U.S. Provisional Application No.61/523,132, filed Aug. 12, 2011, entitled “Hybrid Automatic RepeatRequest in Multicarrier Systems,” which are hereby incorporated byreference in their entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present inventionare described herein with reference to the drawings, in which:

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention;

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentinvention;

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention;

FIG. 4 is a block diagram of a base station and a wireless device as peran aspect of an embodiment of the present invention;

FIG. 5 is a block diagram depicting a system for transmitting datatraffic over an OFDM radio system as per an aspect of an embodiment ofthe present invention;

FIG. 6 is a diagram depicting example time and frequency resources fortwo downlink carriers as per an aspect of an embodiment of the presentinvention;

FIG. 7 is a diagram illustrating a synchronization channel, data channeland control channel as per an aspect of an embodiment of the presentinvention;

FIG. 8 is a diagram depicting example control and data transmission fordownlink carriers and uplink carriers as per an aspect of an embodimentof the present invention; and

FIG. 9 is a diagram depicting example control and data transmission fordownlink carriers and uplink carriers as per an aspect of an embodimentof the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present invention implement multicarrier OFDMcommunications. Example embodiments of the technology disclosed hereinmay be employed in the technical field of multicarrier communicationsystems. More particularly, the embodiments of the technology disclosedherein may relate to transmission and reception of control and datatraffic in a multicarrier OFDM communication system.

Example embodiments of the invention may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CDMA (codedivision multiple access), OFDM (orthogonal frequency divisionmultiplexing), TDMA (time division multiple access), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement QAM (quadrature amplitudemodulation) using BPSK (binary phase shift keying), QPSK (quadraturephase shift keying), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physicalradio transmission may be enhanced by dynamically or semi-dynamicallychanging the modulation and coding scheme depending on transmissionrequirements and radio conditions.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention. As illustrated in thisexample, arrow(s) in the diagram may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, SC-OFDM (single carrier-OFDM) technology, or the like.For example, arrow 101 shows a subcarrier transmitting informationsymbols. FIG. 1 is for illustration purposes, and a typical multicarrierOFDM system may include more subcarriers in a carrier. For example, thenumber of subcarriers in a carrier may be in the range of 10 to 10,000subcarriers. FIG. 1 shows two guard bands 106 and 107 in a transmissionband. As illustrated in FIG. 1, guard band 106 is between subcarriers103 and subcarriers 104. The example set of subcarriers A 102 includessubcarriers 103 and subcarriers 104. FIG. 1 also illustrates an exampleset of subcarriers B 105. As illustrated, there is no guard band betweenany two subcarriers in the example set of subcarriers B 105. Carriers ina multicarrier OFDM communication system may be contiguous carriers,non-contiguous carriers, or a combination of both contiguous andnon-contiguous carriers.

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentinvention. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 10 carriers. Carrier A 204and carrier B 205 may have the same or different timing structures.Although FIG. 2 shows two synchronized carriers, carrier A 204 andcarrier B 205 may or may not be synchronized with each other. Differentradio frame structures may be supported for FDD (frequency divisionduplex) and TDD (time division duplex) duplex mechanisms. FIG. 2 showsan example FDD frame timing. Downlink and uplink transmissions may beorganized into radio frames 201. In this example, radio frame durationis 10 msec. Other frame durations, for example, in the range of 1 to 100msec may also be supported. In this example, each 10 ms radio frame 201may be divided into ten equally sized sub-frames 202. Other subframedurations such as including 0.5 msec, 1 msec, 2 msec, and 5 msec mayalso be supported. Sub-frame(s) may consist of two or more slots 206.For the example of FDD, 10 subframes may be available for downlinktransmission and 10 subframes may be available for uplink transmissionsin each 10 ms interval. Uplink and downlink transmissions may beseparated in the frequency domain. Slot(s) may include a plurality ofOFDM symbols 203. The number of OFDM symbols 203 in a slot 206 maydepend on the cyclic prefix length and subcarrier spacing.

In an example case of TDD, uplink and downlink transmissions may beseparated in the time domain. According to some of the various aspectsof embodiments, each 10 ms radio frame may include two half-frames of 5ms each. Half-frame(s) may include eight slots of length 0.5 ms andthree special fields: DwPTS (Downlink Pilot Time Slot), GP (GuardPeriod) and UpPTS (Uplink Pilot Time Slot). The length of DwPTS andUpPTS may be configurable subject to the total length of DwPTS, GP andUpPTS being equal to 1 ms. Both 5 ms and 10 ms switch-point periodicitymay be supported. In an example, subframe 1 in all configurations andsubframe 6 in configurations with 5 ms switch-point periodicity mayinclude DwPTS, GP and UpPTS. Subframe 6 in configurations with 10 msswitch-point periodicity may include DwPTS. Other subframes may includetwo equally sized slots. For this TDD example, GP may be employed fordownlink to uplink transition. Other subframes/fields may be assignedfor either downlink or uplink transmission. Other frame structures inaddition to the above two frame structures may also be supported, forexample in one example embodiment the frame duration may be selecteddynamically based on the packet sizes.

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention. The resource grid structure intime 304 and frequency 305 is illustrated in FIG. 3. The quantity ofdownlink subcarriers or resource blocks (RB) (in this example 6 to 100RBs) may depend, at least in part, on the downlink transmissionbandwidth 306 configured in the cell. The smallest radio resource unitmay be called a resource element (e.g. 301). Resource elements may begrouped into resource blocks (e.g. 302). Resource blocks may be groupedinto larger radio resources called Resource Block Groups (RBG) (e.g.303). The transmitted signal in slot 206 may be described by one orseveral resource grids of a plurality of subcarriers and a plurality ofOFDM symbols. Resource blocks may be used to describe the mapping ofcertain physical channels to resource elements. Other pre-definedgroupings of physical resource elements may be implemented in the systemdepending on the radio technology. For example, 24 subcarriers may begrouped as a radio block for a duration of 5 msec.

Physical and virtual resource blocks may be defined. A physical resourceblock may be defined as N consecutive OFDM symbols in the time domainand M consecutive subcarriers in the frequency domain, wherein M and Nare integers. A physical resource block may include M×N resourceelements. In an illustrative example, a resource block may correspond toone slot in the time domain and 180 kHz in the frequency domain (for 15KHz subcarrier bandwidth and 12 subcarriers). A virtual resource blockmay be of the same size as a physical resource block. Various types ofvirtual resource blocks may be defined (e.g. virtual resource blocks oflocalized type and virtual resource blocks of distributed type). Forvarious types of virtual resource blocks, a pair of virtual resourceblocks over two slots in a subframe may be assigned together by a singlevirtual resource block number. Virtual resource blocks of localized typemay be mapped directly to physical resource blocks such that sequentialvirtual resource block k corresponds to physical resource block k.Alternatively, virtual resource blocks of distributed type may be mappedto physical resource blocks according to a predefined table or apredefined formula. Various configurations for radio resources may besupported under an OFDM framework, for example, a resource block may bedefined as including the subcarriers in the entire band for an allocatedtime duration.

According to some of the various aspects of embodiments, an antenna portmay be defined such that the channel over which a symbol on the antennaport is conveyed may be inferred from the channel over which anothersymbol on the same antenna port is conveyed. In some embodiments, theremay be one resource grid per antenna port. The set of antenna port(s)supported may depend on the reference signal configuration in the cell.Cell-specific reference signals may support a configuration of one, two,or four antenna port(s) and may be transmitted on antenna port(s) {0},{0, 1}, and {0, 1, 2, 3}, respectively. Multicast-broadcast referencesignals may be transmitted on antenna port 4. Wireless device-specificreference signals may be transmitted on antenna port(s) 5, 7, 8, or oneor several of ports {7, 8, 9, 10, 11, 12, 13, 14}. Positioning referencesignals may be transmitted on antenna port 6. Channel state information(CSI) reference signals may support a configuration of one, two, four oreight antenna port(s) and may be transmitted on antenna port(s) 15, {15,16}, {15, . . . , 18} and {15, . . . , 22}, respectively. Variousconfigurations for antenna configuration may be supported depending onthe number of antennas and the capability of the wireless devices andwireless base stations.

According to some embodiments, a radio resource framework using OFDMtechnology may be employed. Alternative embodiments may be implementedemploying other radio technologies. Example transmission mechanismsinclude, but are not limited to: CDMA, OFDM, TDMA, Wavelet technologies,and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, andOFDM/CDMA may also be employed.

FIG. 4 is an example block diagram of a base station 401 and a wirelessdevice 406, as per an aspect of an embodiment of the present invention.A communication network 400 may include at least one base station 401and at least one wireless device 406. The base station 401 may includeat least one communication interface 402, at least one processor 403,and at least one set of program code instructions 405 stored innon-transitory memory 404 and executable by the at least one processor403. The wireless device 406 may include at least one communicationinterface 407, at least one processor 408, and at least one set ofprogram code instructions 410 stored in non-transitory memory 409 andexecutable by the at least one processor 408. Communication interface402 in base station 401 may be configured to engage in communicationwith communication interface 407 in wireless device 406 via acommunication path that includes at least one wireless link 411.Wireless link 411 may be a bi-directional link. Communication interface407 in wireless device 406 may also be configured to engage in acommunication with communication interface 402 in base station 401. Basestation 401 and wireless device 406 may be configured to send andreceive data over wireless link 411 using multiple frequency carriers.According to some of the various aspects of embodiments, transceiver(s)may be employed. A transceiver is a device that includes both atransmitter and receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in communicationinterface 402, 407 and wireless link 411 are illustrated are FIG. 1,FIG. 2, and FIG. 3. and associated text.

FIG. 5 is a block diagram depicting a system 500 for transmitting datatraffic generated by a wireless device 502 to a server 508 over amulticarrier OFDM radio according to one aspect of the illustrativeembodiments. The system 500 may include a Wireless CellularNetwork/Internet Network 507, which may function to provide connectivitybetween one or more wireless devices 502 (e.g., a cell phone, PDA(personal digital assistant), other wirelessly-equipped device, and/orthe like), one or more servers 508 (e.g. multimedia server, applicationservers, email servers, or database servers) and/or the like.

It should be understood, however, that this and other arrangementsdescribed herein are set forth for purposes of example only. As such,those skilled in the art will appreciate that other arrangements andother elements (e.g., machines, interfaces, functions, orders offunctions, etc.) may be used instead, some elements may be added, andsome elements may be omitted altogether. Further, as in mosttelecommunications applications, those skilled in the art willappreciate that many of the elements described herein are functionalentities that may be implemented as discrete or distributed componentsor in conjunction with other components, and in any suitable combinationand location. Still further, various functions described herein as beingperformed by one or more entities may be carried out by hardware,firmware and/or software logic in combination with hardware. Forinstance, various functions may be carried out by a processor executinga set of machine language instructions stored in memory.

As shown, the access network may include a plurality of base stations503 . . . 504. Base station 503 . . . 504 of the access network mayfunction to transmit and receive RF (radio frequency) radiation 505 . .. 506 at one or more carrier frequencies, and the RF radiation mayprovide one or more air interfaces over which the wireless device 502may communicate with the base stations 503 . . . 504. The user 501 mayuse the wireless device (or UE: user equipment) to receive data traffic,such as one or more multimedia files, data files, pictures, video files,or voice mails, etc. The wireless device 502 may include applicationssuch as web email, email applications, upload and ftp applications, MMS(multimedia messaging system) applications, or file sharingapplications. In another example embodiment, the wireless device 502 mayautomatically send traffic to a server 508 without direct involvement ofa user. For example, consider a wireless camera with automatic uploadfeature, or a video camera uploading videos to the remote server 508, ora personal computer equipped with an application transmitting traffic toa remote server.

One or more base stations 503 . . . 504 may define a correspondingwireless coverage area. The RF radiation 505 . . . 506 of the basestations 503 . . . 504 may carry communications between the WirelessCellular Network/Internet Network 507 and access device 502 according toany of a variety of protocols. For example, RF radiation 505 . . . 506may carry communications according to WiMAX (Worldwide Interoperabilityfor Microwave Access e.g., IEEE 802.16), LTE (long term evolution),microwave, satellite, MMDS (Multichannel Multipoint DistributionService), Wi-Fi (e.g., IEEE 802.11), Bluetooth, infrared, and otherprotocols now known or later developed. The communication between thewireless device 502 and the server 508 may be enabled by any networkingand transport technology for example TCP/IP (transport controlprotocol/Internet protocol), RTP (real time protocol), RTCP (real timecontrol protocol), HTTP (Hypertext Transfer Protocol) or any othernetworking protocol.

According to some of the various aspects of embodiments, an LTE networkmay include many base stations, providing a user plane (PDCP: packetdata convergence protocol/RLC: radio link control/MAC: media accesscontrol/PHY: physical) and control plane (RRC: radio resource control)protocol terminations towards the wireless device. The base station(s)may be interconnected with other base station(s) by means of an X2interface. The base stations may also be connected by means of an S1interface to an EPC (Evolved Packet Core). For example, the basestations may be interconnected to the MME (Mobility Management Entity)by means of the S1-MME interface and to the Serving Gateway (S-GW) bymeans of the S1-U interface. The S1 interface may support a many-to-manyrelation between MMEs/Serving Gateways and base stations. A base stationmay include many sectors for example: 1, 2, 3, 4, or 6 sectors. A basestation may include many cells, for example, ranging from 1 to 50 cellsor more. A cell may be categorized, for example, as a primary cell orsecondary cell. When carrier aggregation is configured, a wirelessdevice may have one RRC connection with the network. At RRC connectionestablishment/re-establishment/handover, one serving cell may providethe NAS (non-access stratum) mobility information (e.g. TAI-trackingarea identifier), and at RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, the carriercorresponding to the PCell may be the Downlink Primary Component Carrier(DL PCC), while in the uplink, it may be the Uplink Primary ComponentCarrier (UL PCC). Depending on wireless device capabilities, SecondaryCells (SCells) may be configured to form together with the PCell a setof serving cells. In the downlink, the carrier corresponding to an SCellmay be a Downlink Secondary Component Carrier (DL SCC), while in theuplink, it may be an Uplink Secondary Component Carrier (UL SCC). AnSCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,is assigned a physical cell ID and a cell index. A carrier (downlink oruplink) belongs to only one cell, the cell ID or Cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the specification, cell ID may be equallyreferred to a carrier ID, and cell index may be referred to carrierindex. In implementation, the physical cell ID or cell index may beassigned to a cell. Cell ID may be determined using the synchronizationsignal transmitted on a downlink carrier. Cell index may be determinedusing RRC messages. For example, when the specification refers to afirst physical cell ID for a first downlink carrier, it may mean thefirst physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the specification indicates that a first carrier is activated, itequally means that the cell comprising the first carrier is activated.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in wireless device, base station, radio environment, network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, traffic load, initial systemset up, packet sizes, traffic characteristics, a combination of theabove, and/or the like. When the one or more criteria are met, theexample embodiments may be applied. Therefore, it may be possible toimplement example embodiments that selectively implement disclosedprotocols.

In carrier aggregation, two or more carriers may be aggregated in orderto support wider transmission bandwidths. A wireless device maysimultaneously receive or transmit on one or multiple carriers dependingon its capabilities. An LTE Rel-10 or above wireless device withreception and/or transmission capabilities for carrier aggregation maysimultaneously receive and/or transmit on multiple carrierscorresponding to multiple serving cells. An LTE Rel-8/9 wireless devicemay receive on a single carrier and transmit on a single carriercorresponding to one serving cell. Carrier aggregation may be supportedfor both contiguous and non-contiguous carriers. A carrier may comprisea plurality of resource blocks in the frequency domain. A wirelessdevice may be configured to aggregate a different number of carriersoriginating from the same base station and of possibly differentbandwidths in the uplink and the downlink. The number of downlinkcarriers that may be configured may depend, at least in part, on thedownlink aggregation capability of the wireless device. The number ofuplink carriers that may be configured may depend, at least in part, onthe uplink aggregation capability of the wireless device. A wirelessdevice may not be configured with more uplink carriers than downlinkcarriers. In typical TDD deployments, the number of carriers and thebandwidth of a carrier in uplink and downlink may be the same. Carriersoriginating from the same base station may or may not provide the samecoverage.

According to the LTE release 10 standard, carriers should be LTE Rel-8/9compatible. Existing mechanisms (e.g. barring) may be used to avoidRel-8/9 wireless devices to camp on a given carrier. The backwardcompatibility of release 10 carriers may introduce additional overheadand reduce air interface spectral efficiency. To overcome this issue, anew carrier type, called non-prime carriers in this specification, maybe introduced for carrier aggregation to enhance spectral efficiency,improve support for overlapping cells and increase energy efficiency.Non-prime carriers may not include the same radio structure as legacycarriers and may not be backward compatible. Legacy carriers aresometimes referred to prime carriers in this specification. A primecarrier is different from a primary carrier as defined in LTE release10. A prime carrier in this specification may be a legacy carrier, forexample, a carrier compatible with LTE release 8, 9, or 10. Primecarriers may comprise primary carriers and secondary carriers as definedin LTE release 10. In this specification, a prime carrier may be abackward compatible carrier and may be a primary carrier or a secondarycarrier.

According to some of the various aspects of embodiments, enhancedspectral efficiency may be possible by removing or reducing some legacycontrol signaling and overhead (for example, PSS, SSS, PBCH, SIB, PCH,PDCCH, and/or the like) and/or common reference signal symbols in thedownlink. In an example embodiment, some of the legacy control signalingoverhead may be maintained, for example, PSS/SSS may be transmitted inunsynchronized non-prime carriers. Spectral efficiency in the downlinkof non-prime carriers may be improved. An enhanced PDCCH for a non-primecarrier may be adopted instead of legacy PDCCH to improve the spectralefficiency of the downlink control channel. The enhanced PDCCH may alsoimprove network performance in overlapping cells. A non-prime carriermay be implemented without legacy PDCCH. Common reference signaloverhead may be removed or reduced. The changes in PDCCH and commonreference signal may improve network performance in overlapping cells.In an example embodiment, a subframe may become empty or include areduced number of symbols. This may reduce power consumption in the basestation. A base station may be configured to: not transmit any signal ina subframe (for example, enter sleep mode or a power saving mode);and/or reduce power consumption when the base station does not transmitany data packet or control packets in that subframe. In prime carriers,a base station may transmit signals in all subframes, even the almostblank subframes. In a non-prime carrier, there may be at least onesub-frame in which the base station does not transmit any data, control,or reference signals on the non-prime carrier.

According to some of the various aspects of embodiments, a non-primecarrier may be associated with a prime carrier (backward compatiblecarrier). A non-prime carrier may not be configured as a primary carrierand may serve as a secondary carrier. An uplink primary carrier maycontain PUCCH radio resources. The uplink non-prime carrier may beconfigured to operate without PUCCH radio resources. In LTE Rel-10, theprimary cell configuration and PUCCH configuration may be wirelessdevice-specific. In legacy LTE uplink carriers (Release 10 and before),resource blocks at the two ends of an uplink carrier may be allocated toPUCCH radio resources. A non-prime carrier may be configured to operatewithout PUCCH. Resource blocks at the two ends of the uplink carrier maybe available for PUSCH transmission. In another example embodiment, anon-prime carrier may be configured to operate without any uplink randomaccess channel resources. The uplink timing of a non-prime carrier maybe tied to a prime uplink carrier.

In an example embodiment, a non-prime carrier may be configured tooperate as a synchronous carrier with another carrier. In anotherexample embodiment, a non-prime carrier may operate as an unsynchronizedcarrier. In synchronized non-prime carriers, the legacy and additionalnon-prime carriers may be synchronized in time and frequency. A minimumor a reduced synchronization processing may be needed in the receiver.Synchronization is considered from the perspective of the wirelessdevice receiver. In unsynchronized non-prime carriers, the legacy andadditional carriers may not be synchronized with the same degree ofaccuracy as for the synchronized carriers. In unsynchronized non-primecarriers, the associated legacy and additional carriers may operatewithout being synchronized with the same degree of accuracy as for thesynchronized carriers. Wireless devices may need to performsynchronization on unsynchronized non-prime carriers. In an exampleembodiment, when a non-prime carrier and the associated prime carrierare in the same band or have adjacent frequencies, the two carriers maybe considered as synchronized. In another example embodiment, when anon-prime carrier and the associated prime carrier are in two differentbands, the two carriers may be considered as unsynchronized carrierswith respect to the wireless device. In an example embodiment, an LTEnetwork and/or a wireless device may support synchronized non-primecarriers, unsynchronized non-prime carriers, none of them, or both ofthem. Some wireless devices may be configured to not support any type ofnon-prime carriers. Some wireless devices may support synchronizednon-prime carriers, or unsynchronized non-prime carriers or both.Network overhead and signaling may be implemented differently insynchronized non-prime and unsynchronized non-prime carriers.

According to some of the various aspects of embodiments, a wirelessdevice may need to identify the type of a non-prime carrier before usingthe non-prime carrier. This may be achieved by higher layer signaling(RRC signaling) or a wireless device may detect a carrier type by itself(for example, by autonomous wireless device detection). In an exampleembodiment, a non-prime carrier type may be configured as anunsynchronized non-prime carrier or as a synchronized non-prime carrier.When a base station configures a non-prime carrier for a wirelessdevice, the wireless device may be informed of the carrier type by thebase station. In an example embodiment, the wireless device may beinformed that a configured non-prime carrier is a synchronized carrier.Information to identify a reference associated carrier fortime/frequency tracking of a synchronized carrier may be configured in awireless device via higher layer signaling (RRC signaling). In anexample embodiment, a synchronized non-prime carrier may be configuredto operate without transmitting PSS/SSS. The wireless device may skipfurther synchronization on the non-prime carrier and may depend on theassociated legacy carrier (prime carrier) timing. In another exampleembodiment, PSS/SSS may be transmitted in a synchronous non-primecarrier. In an example embodiment, a wireless device may be informedthat a configured non-prime carrier is an unsynchronized carrier. Thewireless device may perform synchronization by detecting PSS/SSS and/orcommon reference signal on the non-prime carrier.

According to some of the various aspects of embodiments, in non-primecarriers, the demodulation reference signal may be used for demodulationpurposes. The existing demodulation reference signal patterns may beused on a non-prime carrier. In an example embodiment, demodulationreference signal may be punctured if it overlaps with other signals onthe same radio resources. The common reference signal (common referencesignal) may be configured to not be transmitted in every subframe toreduce common reference signal overhead. In an example embodiment, anon-prime carrier may carry one reference signal port within onesubframe with a 5 ms periodicity. For example, one reference signal portmay comprise LTE common reference signal port 0 resource elements perphysical resource block and Rel-8 common reference signal sequence. Insome embodiments, common reference signal may not be used fordemodulation. Bandwidth of the reference signal port may be one of: (a)a full carrier bandwidth; (b) the minimum of system bandwidth and X,where X is for example 6 or 25 resource blocks; and (c) configurable(for example by RRC signaling) between full system bandwidth and theminimum of system bandwidth and X. For example, X may be selected from 6or 25 resource blocks. In a synchronized non-prime carrier, commonreference signal overhead may be reduced compared with legacy carriers.For example, common reference signal in a synchronized non-prime carriermay be the same as common reference signal in an unsynchronizednon-prime carrier. In another example embodiment, common referencesignal overhead may be further reduced compared with unsynchronizednon-prime carriers or may not be transmitted.

Non-prime carriers may be configured to not support all transmissionmodes. For example, transmission modes 1 to 8 may not be supported on anon-prime carrier, since the radio resource configuration may not becompatible with transmission modes 1 to 8. In an example embodiment,multiple layers of transmissions may be supported on a non-primecarrier. For example, up to eight layer transmission schemes may besupported on a non-prime carrier.

According to some of the various aspects of embodiments, for FDD: SSSand PSS may be transmitted in OFDM symbol 1 and 2, respectively; and maybe transmitted in the first slot of subframe 0 and 5 with normal andextended cyclic prefix. For TDD, the OFDM symbol spacing and orderingbetween SSS and PSS may be the same as Rel-8. In an example embodiment,SSS may precede PSS. There may be two OFDM symbols between SSS and PSS.The location of SSS and PSS in time may be the same or different whencompared with legacy carriers.

Potential motivations for changing the time/frequency location relativeto LTE Rel-8, may be: preventing acquisition of a new carrier; reducinginter-cell interference; and avoiding demodulation reference signaloverlap in central 6 physical resource blocks. In an example embodiment,the time location of the PSS/SSS in a frame and/or subframe may bechanged and the frequency location of PSS/SSS may not be changed. ThePSS/SSS may be transmitted at a different location in time in the sameor different subframe compared with prime carriers. There may be nooverlap between PSS/SSS radio resources of a prime carrier and anon-prime carrier operating in the same frequency. This may reducePSS/SSS interference in overlapping areas. PSS/SSS configuration, suchas the location and/or sequences of PSS/SSS may be pre-defined or may becommunicated to a wireless device via higher layer signaling. Thewireless device then may acquire the PSS/SSS of a non-prime carrier fortime and/or frequency synchronization.

According to some of the various aspects of embodiments, PSS/SSStransmission on non-prime carriers may collide with demodulationreference signal. Many implementation options may be available toaddress this issue. For example, demodulation reference signal may bepunctured when colliding with PSS/SSS to resolve the collision betweenPSS/SSS and demodulation reference signal. The non-prime carrier may usewireless device-specific reference signal for demodulation. On thelegacy carrier, the wireless device-specific reference signal may beconfigured to not transmit in subframe 0 and subframe 5 in the central 6resource blocks since the PSS/SSS transmitted in these resource blocksoverlaps with the wireless device-specific reference signal locations.The motive for changing the PSS/SSS time locations would be to addressthe case where the PSS/SSS collide with the demodulation referencesignal. In an example embodiment, LTE Rel-10 procedure may be employedand the demodulation reference signal may not be transmitted in theresource blocks where the PSS/SSS are transmitted. The difference withRel-10, is that for an additional carrier type in Rel-11, commonreference signal overhead may be reduced and common reference signal maynot to be used for demodulation purposes. If the Rel-10 procedure isapplied (dropping demodulation reference signal), the consequence may bea reduced spectral efficiency. In another example embodiment, the samesequences as release 8 may be employed for PSS/SSS and PSS/SSS timelocations may be changed. It may be possible to use the same (orsimilar) cell searcher as used in legacy carriers (in Rel-8/9/10).

According to some of the various aspects of embodiments, for the cellacquisition/detection of a non-prime carrier, legacydetection/acquisition signals may be employed for a non-prime carrier.New time/frequency configurations of existing signals may beimplemented. For unsynchronized non-prime carriers, Rel-8 PSS/SSSsequences may be transmitted. The time-frequency location of PSS/SSSrelative to Rel-8 may be changed to prevent the acquisition of anon-prime carrier. Inter-cell carrier interference may reduce thereliability of synchronization signals (PSS/SSS) and broadcastinformation (PBCH) between interfering cells (for example between amacro cell and a small cell). A new time location of PSS/SSS may beapplied on a non-prime carrier for interference co-ordinations so thatthe collision of the synchronization signals between interfering cellsmay be reduced or avoided.

According to some of the various aspects of embodiments, a wirelessdevice supporting unsynchronized non-prime carrier may support thefunctionality of performing time/frequency synchronization on thenon-prime carrier using the PSS/SS transmitted on that non-primecarrier. Implementation of synchronization in a synchronized non-primecarrier may be simpler and a wireless device may obtain synchronizationinformation from the associated prime carrier. In an example embodiment,a synchronized non-prime carrier may be configured to operate withoutPSS/SSS transmission for use in time and frequency tracking. A wirelessdevice may use the synchronization obtained from the associated primecarrier. If PSS/SSS are not transmitted on the synchronized carriers,then demodulation reference signal puncturing or other solutions forPSS/SSS may not be needed to avoid the collision between PSS/SSS anddemodulation reference signal. In another example embodiment, PSS/SSSmay be transmitted on a synchronous non-prime carrier. A synchronizedreference carrier may be a legacy carrier (prime carrier) synchronizedwith a synchronized non-prime carrier in time and/or frequency. In orderto obtain synchronization information of the synchronized non-primecarrier, synchronization information of the synchronization referencecarrier may be employed. The synchronization reference carrier may beconfigured in a wireless device via higher-layer signaling.

A mechanism may be implemented to prevent a wireless device (forexample, an LTE release 8, 9 or 10 wireless device) from acquiring thePSS/SSS of a non-prime carrier (e.g. during the cell search process).The mechanism may be implemented at the physical layer or at higherlayers. A wireless device may search for the legacy cells and may attachto a cell that transmits the legacy PSS/SSS. The wireless device mayreceive configuration information of carriers that the wireless devicemay employ for communications using carrier aggregation. The carrierconfiguration information may include, for example, FDD/TDDconfiguration, cyclic Prefix type, bandwidth, cell index/ID, uplinkconfiguration, downlink configuration, configuration for physicalchannels, associated prime carrier, cross carrier schedulingconfiguration, a combination of the above, and/or the like.

According to some of the various aspects of embodiments, wirelessdevices may consider the new time location of PSS/SSS radio resources toidentify a non-prime carrier type and not to spend considerableresources on any subsequent procedures after PSS/SSS acquisition (andbefore being barred from further camping on the non-prime type at alater stage). Physical layer procedures may be employed to distinguish aprime carrier from a non-prime carrier. The wireless device may searchfor the prime carriers and may be configured to not look for non-primecarriers. In an example embodiment, a physical a new time location ofPSS/SSS may not be effective mechanism to bar legacy devices. A wirelessdevice may be able to decode the new PSS (e.g., if the new PSS isidentical to the old PSS except a certain symbol offset), depending onimplementation, and the wireless device may identify a successful SSSdecoding. In an example embodiment, physical layer mechanisms mayprevent legacy wireless devices from acquiring non-prime carriers. Inanother example embodiment, legacy wireless devices may be preventedfrom acquiring non-prime carriers by higher layers. If physical layermechanism does not prevent legacy wireless devices from acquiringnon-prime carries, wireless devices may be able to detect/acquire thecell of a non-prime carrier and may try to select/reselect a non-primecell. This may degrade legacy wireless devices' performance in cellselection/reselection. If PSS/SSS of a non-prime cell is non-visible bylegacy wireless devices and/or is distinguishable by legacy wirelessdevices, legacy wireless devices may not be able to select/reselect thenon-prime cell. This may be a solution for legacy wireless devices, andit may enable Rel-11 wireless devices to differentiate non-primecarriers from prime carriers by PSS/SSS detection.

If a wireless device physical layer does not detect the differencesbetween prime and non-prime carriers, and if legacy wireless devicephysical layer detects/acquires a non-prime carrier, then wirelessdevice may employ higher layer signaling rules to prevent measurement,selecting and/or reselecting a non-prime cell. A wireless device may notbe able to receive higher layer signaling information on a non-primecarrier, for example broadcast control channel. Wireless device behaviorwhen higher level essential information is missing may be triggered andhigher layer signaling may prevent legacy wireless devices fromselecting/reselecting a non-prime cell. The higher layer mechanisms maybe implemented to prevent legacy wireless devices access to non-primecells.

Since non-prime carriers may operate jointly with backward compatiblecarriers (prime carriers) and may only operate in an RRC connectedstate, a wireless device may obtain some RRC information (for example,cell configuration parameters) before accessing non-prime carriers. Inan example embodiment, non-prime carriers may be configured to operatewithout transmitting PBCH and/or other system information blocks. Pagingmay be configured to be transmitted on prime carriers, which may includea primary cell for a wireless device. Paging may be configured to nottransmit on non-prime carriers. Random access responses may be supportedonly on a primary carrier. Common control channels may be configured tobroadcast on prime carriers. Non-primary carriers may be configured tonot broadcast common control channels. Non-prime carriers may beconfigured to operate without common search space on physical controlchannel. Common search space may be defined exclusively for PDCCHresources in a primary carrier.

According to some of the various aspects of embodiments, enhanced PDCCHon a non-prime carrier may be supported. Cross-carrier scheduling fromanother carrier, for example the associated prime carrier, may besupported. A cross-carrier scheduling scheme may be implemented forresource allocation on non-prime carriers. Enhanced PDCCH may betransmitted on a non-prime carrier. Non-prime carriers may be configuredto operate without transmitting legacy PDDCH. Cross carrier schedulingfrom another carrier employing a carrier indication field may beconfigured. The usage of enhanced PDCCH and cross carrier scheduling maybe configurable using RRC messages. Enhanced PDCCH configuration of anon-prime carrier may be communicated to a wireless device employing RRCsignaling when the non-prime carrier is configured. Enhanced PDDCHconfiguration parameters may comprise a frequency offset and/orbandwidth in terms of resource blocks. In an example embodiment,additional fields such as: the starting symbol of an enhanced PDCCH, thestarting symbol of PDSCH, an enhanced PHICH configuration, a combinationof the above, and/or the like may be configured for a non-prime carrierin the wireless device. These parameters may be configured via RRCsignaling, for example when a non-prime carrier is configured.

A non-prime carrier may be configured to operate without PCFICH. Anenhanced PDCCH configuration may be transmitted to the wireless deviceemploying RRC signaling. When cross carrier scheduling is used, thePHICH for the non-prime uplink carrier may be transmitted on thescheduling downlink carrier. In an example embodiment, when enhancedPDCCH on a non-prime carrier is implemented, enhanced PHICH on thenon-prime carrier may be configured. Radio resources of enhanced PHICHmay employ the resource blocks employed for the enhanced PDCCH of anon-prime carrier. The enhanced PHICH and enhanced PDCCH on a non-primecarrier may employ different resource elements if a given resourceblock. The resource elements may not be shared between enhanced PDCCHand enhanced PHICH. In another example embodiment, PHICH may betransmitted on the associated prime carrier. PHICH or enhanced PHICH maybe transmitted on a downlink carrier. PHICH or enhanced PHICH for anuplink carrier may carry ack/nack for packets transmitted on the uplinkcarrier.

In an example embodiment, non-prime carriers may be configured tooperate without transmitting PBCH, SIBs, paging messages, random accessresponses, legacy PDCCH, PCFICH, a combination of the above, and/or thelike. In another example embodiment, some of control channels, forexample PBCH, may be maintained in a non-prime carrier. Common referencesignal symbols overhead may also be reduced compared with primecarriers.

According to some of the various aspects of embodiments, non-primecarriers may be employed to reduce inter-cell interference. In legacysystems, synchronization signals of different carriers transmitted inthe same frequency may interfere with each other. In an exampleembodiment, the PSS/SSS of a prime carrier may be configured to notoverlap with PSS/SSS of a non-prime carrier. In another exampleembodiment, synchronized non-prime carriers may be configured to operatewithout transmitting PSS/SSS. This may reduce interference due tosynchronization signals on other downlink carriers transmitted in thesame frequency in the overlapping coverage areas. In an exampleembodiment, common reference signal overhead may be reduced in non-primedownlink carriers. Reduction in common reference signal transmission innon-prime carriers compared with prime carriers may reduce interferencedue to common reference signals on other downlink carriers transmittedin the same frequency.

According to some of the various aspects of embodiments, the startingsymbol of enhanced PDCCH and/or PDSCH on a non-prime carrier may beconfigurable in all or a subset of subframes of a non-prime carrier. Atleast one RRC reconfiguration message may indicate the configurationparameters of a non-prime carrier to the wireless device, includingenhanced PDCCH and PDSCH configuration parameters and subframes that theconfiguration is applicable. For example, the starting symbol may beconfigured as the first, second, third, or forth symbol in a subset ofsubframes or all subframes. If PDSCH and/or enhanced PDCCH start, forexample, from the third symbol in a subframe, no or a substantiallyreduced signal power may be transmitted in the first and second symbolsof a subframe. The initial symbols (first and second symbols of a subsetor all subframes in this example) on another prime downlink carrieroperating on the same frequency may be employed for transmission ofPDCCH. Such a configuration may reduce inter-cell interference betweencells with an overlapping coverage area operating in the same frequency.A more reliable PDCCH transmission may be achieved. For example, apotential interferer non-prime cell may be configured to not transmit ata high power when another prime cell is transmitting PCFICH/PDCCH/PHICHsymbols in the same cell frequency. In another example embodiment,enhanced PDCCH and PDSCH on a non-prime carrier may start from the firstsymbol to increase physical resources available to enhanced PDCCH andPDSCH of a non-prime carrier. In this configuration, the first symbol ofa frame may be used for control and data transmission, and base stationmay start enhanced PDCCH and PDSCH transmission from the first symbol ofa frame and end at the last symbol of the subframe.

According to some of the various aspects of embodiments, a non-primecarrier may include enhanced PDCCH resources. Enhanced PDCCH may act asPDCCH for the non-prime carrier. Enhanced PDCCH may carry schedulinginformation for downlink and uplink shared channels and may also carrypower control information for uplink transmissions. Beamforming and/orspecial multiplexing may be employed for enhanced PDCCH. For example,scheduling packets of two different wireless devices may share the sameenhanced PDCCH resources using spatial multiplexing techniques. Anon-prime carrier may not be initially defined for standalone operation.A non-prime carrier may be associated with a backward compatiblecarrier. In an example embodiment, a non-prime carrier may becontiguously deployed next to the associated prime carrier. In anon-prime carrier, PDSCH may be scheduled independently from the otheraggregated carriers employing enhanced PDCCH and with independent HARQprocesses. PDSCH in a non-prime carrier may be cross-carrier scheduledby the other aggregated carrier.

In case of cross-carrier scheduling in LTE Rel-10 carrier aggregation,the PDSCH of a carrier may be cross carrier scheduled by PDCCH ofanother carrier. The PDSCH starting position of the scheduled carriermay be RRC-signaled to the wireless device. In LTE Rel-10 carrieraggregation, the starting position of PDSCH cannot be configured to bethe first symbol. PCFICH transmission is mandatory, and PDCCH and PHICHshould be configured. PDCCH transmission should be supported in allsubframes. At least transmission of system information blocks and/orother necessary control information should be supported on a carrierwithout employing cross carrier scheduling, and this require PDCCHresources of the carrier. The mandatory configuration of PCFICH, PDCCH,and/or PHICH on carriers including carriers that are cross carrierscheduled may reduce spectral efficiency in release 10 or before LTEcarriers. Furthermore, in legacy systems the starting symbol of PCFICHand PDCCH is not configurable and should always start from the firstsymbol in LTE subframes.

A non-prime carrier may be configured to not transmit enhanced PDCCHand/or PDSCH in its starting OFDM symbol(s) in a subframe. A basestation may configure the starting OFDM symbol(s) in a subframe of anon-prime carrier in order to reduce transmission power in some ofinitial OFDM symbols for the purpose of interference coordination (e.g.scenarios where one cell employs legacy PDCCH and another cell employsenhanced PDCCH). The PDSCH and/or enhanced PDCCH starting position of anon-prime carrier may be transmitted to the wireless device employingRRC messages. A non-prime carrier may be configured to not carry thelegacy PDCCH. The RRC signaling for non-prime carrier configuration mayindicate the very first OFDM symbol in a subframe as the PDSCH startingposition, unlike legacy LTE systems. The enhanced PDCCH startingposition may be the same as the PDSCH starting position. In anotherexample embodiment, the enhanced PDCCH starting position may not be sameas the PDSCH starting position.

Legacy PDCCH may not be present on a non-prime carrier. In this case,the scheduling may be done through at least one of the following twoways: a) cross-carrier scheduling from another carrier (for example, theassociated backward-compatible carrier or another carrier); or b)enhanced PDCCH may be configured on the non-prime carrier so as toimprove control channel capacity and provide interference coordinationon the control channel. Enhanced PDDCH of interfering cells may beconfigured in a way that enhanced PDDCH of interfering cells may notoverlap or may have reduced overlap in radio resources. If cross-carrierscheduling is employed, there may be no need for PHICH and PCFICH on thenon-prime carrier. The HARQ ack/nack feedback may be transmitted on thescheduling carrier. If enhanced PDCCH is used in a non-prime carrier, aPHICH may be implemented for the non-prime carrier.

The enhanced PDCCH radio resources may be configurable. Theconfiguration may comprise at least one of the following: i) a startingfrequency offset in terms of a first number of radio resource blocks;ii) bandwidth of enhanced physical downlink control channel in terms ofa second number of radio resource blocks; iii) starting time in asubframe in terms of number of symbols; iv) ending time in a subframe interms of slots (or symbols); v) beamforming information for the physicaldownlink control channel, and/or vi) a combination of the some of theparameters above. In an example embodiment, enhanced PDCCH configurationmay be in the form of an array where an element in the array may includethe above parameters. Enhanced PDCCH may include many non-overlappingradio resources in a non-prime carrier.

Example embodiments of the invention may enable transmission andreception of control and data traffic in a multicarrier OFDMcommunication system. Other example embodiments may comprise anon-transitory tangible computer readable media comprising instructionsexecutable by one or more processors to cause transmission and receptionof control and data traffic in a multicarrier OFDM communicationsystems. Yet other example embodiments may comprise an article ofmanufacture that comprises a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a device (e.g. wirelesscommunicator, wireless device, base station, etc.) to enabletransmission and reception of control and data traffic in a multicarrierOFDM communication system. The device may include processors, memory,interfaces, and/or the like. Other example embodiments may comprisecommunication networks comprising devices such as base stations,wireless devices (wireless device), servers, switches, antennas, and/orthe like.

FIG. 6 is a diagram depicting time and frequency resources for primecarrier 601 and non-prime carrier 602 as per an aspect of an embodimentof the present invention. FIG. 7 is a diagram illustratingsynchronization, data and control transmission channels as per an aspectof an embodiment of the present invention. A base station may beconfigured to communicate with wireless devices employing a plurality ofcarriers. A wireless device may be configured to communicate with atleast one base station employing a plurality of carriers. A carrier inthe plurality of carriers may comprise a plurality of OFDM or SC-OFDMsubcarriers. Transmission time may be divided into a plurality ofsubframes, and a subframe in the plurality of subframes may further bedivided into a plurality of OFDM symbols.

A base station may transmit to at least one wireless device asynchronization signal 615, 606, 608, 609 comprising a primarysynchronization signal 606, 609 and a secondary synchronization signal615, 608 on the prime carrier 601. The synchronization signal mayindicate a physical cell ID for a cell comprising the prime carrier 601.The synchronization signal may also provide timing information for theprime carrier 601. The synchronization signal may be transmittedemploying a plurality of subcarriers substantially in the center of thefrequency band of the prime carrier 601 on the first and sixth subframes(subframe 0 and 5) of each frame in the plurality of frames. Primary andsecondary synchronization signals may occupy a bandwidth ofapproximately six resource blocks. The base station may broadcast to atleast one wireless device physical broadcast channel (PBCH) 607 in slotone 604 of subframe 0 of the prime carrier 301. At least one wirelessdevice may receive the synchronization signals to obtain and/or trackcarrier frame and subframe timing. At least one wireless device mayreceive PBCH signal to obtain at least one configuration parameter ofthe downlink carrier.

According to some of the various aspects of embodiments, a base stationmay transmit to at least one wireless device a synchronization signal615, 606, 608, 609 comprising a primary synchronization signal 606, 609and a secondary synchronization signal 615, 608 on the prime carrier601. The synchronization signal may indicate a physical cell ID for acell comprising the prime carrier 601. The synchronization signal mayalso provide timing information for the prime carrier 601 and thenon-prime carrier 602 in the plurality of carriers. The synchronizationsignal may be transmitted employing a plurality of subcarrierssubstantially in the center of the frequency band of the prime carrier601 on the first and sixth subframes (subframe 0 and 5) of each frame inthe plurality of frames. Primary and secondary synchronization signalsmay occupy a bandwidth equal to six resource blocks. A physicalbroadcast channel (PBCH) 607 may be transmitted in slot one 604 ofsubframe 0 of the prime carrier 301. In one example embodiment, radioresources 610, 611, 612, 613 and 614 may not be employed fortransmission of a synchronization signal and PBCH. These resources maybe employed for data transmission on the downlink carrier. For example,these radio resources may be employed for transmission of data packetson a non-prime carrier physical downlink shared channel.

According to some of the various aspects of embodiments, a base stationmay transmit a first synchronization signal 615, 606, 608, 609comprising a primary synchronization signal 606, 609 and a secondarysynchronization signal 615, 608 on the prime carrier 601. The firstsynchronization signal may indicate a physical cell ID for a cellcomprising the prime carrier 601. The first synchronization signal mayprovide timing information for the prime carrier 601. A secondsynchronization signal may be transmitted on the non-prime carrier. Thesecond synchronization signal may be transmitted employing a pluralityof subcarriers substantially in the center of the frequency band of thenon-prime carrier 602 employing six resource blocks. A secondsynchronization signal may comprise a second primary synchronizationsignal and a second secondary synchronization signal. In an exampleembodiment, the second synchronization signal may be transmitted on asecond time location (different from time location of the firstsynchronization signal) in the same or different subframe compared withthe first synchronization signal. The second synchronization signal mayprovide timing information for the non-prime carrier 602.

The base station may transmit to at least one wireless device a firstplurality of data packets on a first data channel 703 of the primecarrier 601 on a first plurality of OFDM subcarriers. A first pluralityof OFDM subcarriers may exclude a plurality of subcarriers used fortransmission of the primary 606, 609 and secondary 615, 608synchronization signals in the first and sixth subframes in theplurality of frames. A first plurality of OFDM subcarriers may exclude aplurality of subcarriers used for transmission of the PBCH 607.PSS/SSS/PBCH resources 709 on the prime carrier 601 in an examplesubframe 708 are illustrated in FIG. 7.

The base station may transmit a first plurality of broadcast systeminformation messages (SIB messages) on the first data channel 703employing, for example, radio resources 704. The plurality of broadcastsystem information messages may comprise a plurality of radio linkconfiguration parameters of the prime carrier 601 for a wireless devicereceiving the prime carrier 601 and the non-prime carrier 602 signals.An example radio resource 704 employed for SIB message transmission isillustrated in FIG. 7. SIB messages may be transmitted continuously andmay be transmitted on a subset of the downlink subframes of the primecarrier 601. System information of the non-prime carrier 602 may bereceived via at least one unicast RRC message when the non-prime carrier602 is configured by higher layers. In an example embodiment, the atleast one unicast RRC message may be transmitted on the first datachannel 703 of the prime carrier 601. The non-prime carrier 602 may beconfigured to operate without broadcasting the system information blockson the non-prime carrier 602. The base station may transmit a secondplurality of data packets on a second data channel 705 on a secondplurality of OFDM subcarriers of the non-prime carrier 602.

According to some of the various aspects of embodiments, the secondplurality of OFDM subcarriers of the non-prime carrier 602 may comprisethe OFDM subcarriers substantially in the center of the frequency bandat symbols 610, 611, 613, and 614 of the non-prime carrier 602 in thefirst and sixth subframes in the plurality of frames. No primarysynchronization signal and no secondary synchronization signal may betransmitted on the second carrier in radio resource 610, 611, 613, and614. The non-prime carrier may be configured to operate withouttransmitting primary synchronization signal and secondarysynchronization signal in radio resource 610, 611, 613, and 614. Nobroadcast system information message (SIB messages) may be transmittedon the second data channel 705. The non-prime carrier 602 may beconfigured to operate without transmitting or broadcasting systeminformation message (SIB messages). No physical broadcast channel may betransmitted in radio resource 612. The non-prime carrier 602 may beconfigured to operate without transmitting physical broadcast channel inradio resource 612. In an example embodiment, if non-prime carrier 602is a synchronized non-prime carrier, subframe timing of the non-primecarrier 602 may be provided by the synchronization signal transmitted onthe prime carrier 601. In another example embodiment, if the non-primecarrier 602 is an unsynchronized non-prime carrier, subframe timing ofthe non-prime carrier 602 may be provided by a second synchronizationsignal transmitted on the non-prime carrier 602. In an exampleembodiment, if synchronization signals are transmitted on a non-primecarrier 602, radio resources 712 of synchronization signal may be in adifferent time location in the same subframe 708 (as shown in FIG. 7) orin a different subframe (not shown in the figure).

The first plurality of data packets and the second plurality of datapackets may be transmitted using a plurality of physical resourceblocks. A physical resource block may comprise reference signal symbolsand data symbols. The broadcast system information messages may be RRCsystem information blocks (SIBs). The radio link configurationinformation may comprise measurement configuration, uplink channelconfiguration, handover parameters, and/or the like.

The primary synchronization signal 606, 609 may be generated using afrequency-domain Zadoff-Chu sequence. The primary synchronization signal606, 609 may be mapped to the last OFDM symbol in slots zero 603 and ten605 for an FDD frame structure. The primary synchronization signal 606,609 may be mapped to the third OFDM symbol in subframes 1 and 6 for theTDD frame structure. The secondary synchronization signal 615, 608 maybe generated employing an interleaved concatenation of two 31 bit binarysequences. The concatenated sequence may be scrambled with a scramblingsequence given by the primary synchronization signal 606, 609. Theportion of the secondary synchronization signal transmitted in subframezero 615 may be different from the portion of the secondarysynchronization signal transmitted in subframe five 608. If a non-primecarrier is configured to transmit synchronization signals, thesynchronization signals transmitted on a prime carrier and thesynchronization signals transmitted on the non-prime carrier may beselected from the same set of available sequences.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina first carrier configuration, the control channel 702 may be configuredto provide transmission format and scheduling information for the firstplurality of data packets transmitted on the prime carrier 601 and thesecond plurality of data packets transmitted on the non-prime carrier602. The control channel 602 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe. The control channelmay be a physical downlink control channel. No physical control formatindicator channels, no physical downlink HARQ indicator channel, and nophysical downlink control channels may be transmitted on the non-primecarrier 602. The non-prime carrier 602 may be configured to operatewithout transmitting physical control format indicator channel, physicaldownlink HARQ indicator channel, and physical downlink control channel.Radio resources of the second data channel 705 may be configured tostart from the first OFDM symbol of a subframe 708 of the non-primecarrier 602 and to end at the last OFDM symbol of the subframe of thenon-prime carrier 602. No HARQ feedback may be transmitted on thenon-prime carrier 602. The non-prime carrier 602 may be configured tooperate without transmitting HARQ feedback on the non-prime carrier 602.

FIG. 9 is a diagram depicting example control and data transmission fora prime downlink carrier 601, a non-prime downlink carrier 602, a primeuplink carrier 811, and a non-prime uplink carrier 812 as per an aspectof an embodiment of the present invention. Downlink subframe 903 may notbe transmitted at the same time with uplink subframe 904. Radioresources 905 are employed for transmission of PCFICH, PDCCH, and PHICH.The downlink control channel (PDCCH) in radio resources 905 may beconfigured to provide transmission format and scheduling information fora first plurality of packets transmitted on a first downlink sharedchannel 906, a second plurality of packets transmitted on a seconddownlink shared channel 907, a third plurality of data packetstransmitted on a first uplink shared channel 908, and a fourth pluralityof data packets transmitted on a second uplink shared channel 909. Forexample control packet 916 may provide transmission format andscheduling information for data packet 913. Control packet 922 mayprovide transmission format and scheduling information for data packet933. Control packet 918 may provide transmission format and schedulinginformation for data packet 914. Control packet 920 may providetransmission format and scheduling information for data packet 924.Control packets 918 and 920 may also comprise power control informationfor transmission of packets 914 and 924 respectively. The prime uplinkcarrier 811 may comprise: a) a first portion of bandwidth employed forthe first uplink data channel 908; and b) a second portion of thebandwidth employed for a first uplink control channel 910.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina second carrier configuration, the control channel 702 may beconfigured to provide transmission format and scheduling information forthe first plurality of data packets transmitted on the prime carrier601. The control channel 702 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe 708. The controlchannel may be a physical downlink control channel. Second controlinformation may be transmitted on a second control channel 711 on thenon-prime carrier 602. The second control channel 711 may be configuredto provide transmission format and scheduling information for the secondplurality of data packets transmitted on the non-prime carrier 602. Thesecond control channel may be an enhanced physical downlink controlchannel. Radio resources of the second data channel 705 may beconfigured to start from the first OFDM symbol of a subframe of thenon-prime carrier 602 and end at the last OFDM symbol of the subframe ofthe non-prime carrier 602.

FIG. 8 is a diagram depicting example control and data transmission fora prime downlink carrier 601, a non-prime downlink carrier 602, a primeuplink carrier 811, and a non-prime uplink carrier 812 as per an aspectof an embodiment of the present invention. Downlink subframe 803 may notbe transmitted at the same time with uplink subframe 804. Radioresources 805 are employed for transmission of PCFICH, PDCCH, and PHICH.The downlink control channel (PDCCH) in radio resources 805 may beconfigured to provide transmission format and scheduling information fora first plurality of packets transmitted on a first downlink sharedchannel 806, and a third plurality of data packets transmitted on afirst uplink shared channel 808. Enhance control channel 824 may beconfigured to provide transmission format and scheduling information fora second plurality of packets transmitted on a second downlink sharedchannel 807, and a fourth plurality of data packets transmitted on asecond uplink shared channel 809. For example control packet 814 mayprovide transmission format and scheduling information for data packet820. Control packet 816 may provide transmission format and schedulinginformation for data packet 830. Control packet 926 may providetransmission format and scheduling information for data packet 818.Control packet 928 may provide transmission format and schedulinginformation for data packet 832. Control packets 816 and 928 may alsocomprise power control information for transmission of packets 830 and832 respectively. The prime uplink carrier 811 may comprise: a) a firstportion of bandwidth employed for the first uplink data channel 808; andb) a second portion of the bandwidth employed for a first uplink controlchannel 810.

FIG. 8 and FIG. 9 illustrate two example carrier configurations. Carrierconfigurations are wireless device specific. A first wireless deviceconnected to a base station may be configured with a first carrierconfiguration and a second wireless device connected to the same basestation may be configured with a second carrier configuration.Therefore, a base station may provide both first and the secondconfigurations. For a first wireless device the base station may employcross carrier scheduling as shown in FIG. 9, and for a second wirelessdevice the base station may employ enhanced PDCCH as shown in FIG. 10. Abase station may support both configurations in parallel, a firstconfiguration may be applied to a first wireless device, and a secondconfiguration may be applied to a second wireless device. For the firstwireless device, the PDCCH in radio resource 905 may be configured toprovide transmission format and scheduling information for a firstplurality of packets transmitted on a first downlink shared channel 906,a second plurality of packets transmitted on a second downlink sharedchannel 907, a third plurality of data packets transmitted on a firstuplink shared channel 908, and a fourth plurality of data packetstransmitted on a second uplink shared channel 909. During the sameperiod, the downlink control channel (PDCCH) in radio resources 805 maybe configured to provide transmission format and scheduling informationfor a first plurality of packets transmitted on a first downlink sharedchannel 806, and a third plurality of data packets transmitted on afirst uplink shared channel 808. Enhance control channel 824 may beconfigured to provide transmission format and scheduling information fora second plurality of packets transmitted on a second downlink sharedchannel 807, and a fourth plurality of data packets transmitted on asecond uplink shared channel 809.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina third carrier configuration, the control channel 702 may be configuredto provide transmission format and scheduling information for the firstplurality of data packets transmitted on the prime carrier 601 and thesecond plurality of data packets transmitted on the non-prime carrier602. The control channel 602 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe. The control channelmay be a physical downlink control channel. No physical control formatindicator channels, no physical downlink HARQ indicator channel, and nophysical downlink control channels may be transmitted on the non-primecarrier 602. The non-prime carrier 602 may be configured to operatewithout transmitting physical control format indicator channel, physicaldownlink HARQ indicator channel, and physical downlink control channel.No HARQ feedback may be transmitted on the non-prime carrier 602. Thenon-prime carrier 602 may be configured to operate without transmittingHARQ feedback on the non-prime carrier 602. The starting symbol of radioresources of the second physical downlink shared channel 705 may beindicated by at least one control message. For example, the startingsymbol of the second physical downlink shared channel 705 may beconfigured to start from the third symbol of a subframe. In thisconfiguration, the first and second symbol of the subframe may not beemployed for transmission of control and data channels. The base stationmay transmit substantially reduced power or no power in the first twosymbols of the subframe. In an implementation option, the ending symbolof the second physical downlink shared channel 705 may be indicated byat least one control message.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina fourth carrier configuration, the control channel 702 may beconfigured to provide transmission format and scheduling information forthe first plurality of data packets transmitted on the prime carrier601. The control channel 702 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe 708. The controlchannel may be a physical downlink control channel. Second controlinformation may be transmitted on a second control channel 711 on thenon-prime carrier 602. The second control channel 711 may be configuredto provide transmission format and scheduling information for the secondplurality of data packets transmitted on the non-prime carrier 602. Thesecond control channel may be an enhanced physical downlink controlchannel. The starting symbol of radio resources of the second physicaldownlink shared channel 705 and/or the second control channel 711 may beindicated by at least one control message. For example, the startingsymbol of the second physical downlink shared channel 705 and/or thesecond control channel 711 may be configured to start from the thirdsymbol of a subframe. In this configuration, the first and second symbolof the subframe may not be employed for transmission of control and datachannels. The base station may transmit substantially reduced power orno power in the first two symbols of the subframe. In an implementationoption, the ending symbol of the second physical downlink shared channel705 and/or the second control channel 711 may be indicated by at leastone control message.

Radio resources 709 may be configured to provide a synchronizationsignal on the prime carrier 601. In an example carrier configuration, ifthe non-prime carrier is configured to carry a synchronization signal,radio resources 712 may be configured to provide the secondsynchronization signal on the non-prime carrier. In another exampleembodiment, the non-prime carrier may be configured to operate withouttransmitting the second synchronization signal. In that case, a wirelessdevice may employ the synchronization signal 709 transmitted on theprime carrier 601 for frame and subframe timing of the prime carrier 601and the non-prime carrier 602.

FIG. 7 is a diagram illustrating synchronization, data and controltransmission channels as per an aspect of an embodiment of the presentinvention. The base station may transmit first control information on afirst control channel on the first OFDM symbol of subframes of a primecarrier 601 in the plurality of carriers. An instance of the firstcontrol channel information may comprise a control format indicator. Thebase station may transmit a plurality of control format indicators onthe first control channel. A control format indicator 701 in theplurality of control format indicators may be transmitted on the firstcontrol channel over the first OFDM symbol in a plurality of OFDMsymbols of the first subframe 708 in a plurality of subframes. The firstcontrol channel may be transmitted in all subframes of the prime carrier601. The plurality of control format indicators may be transmitted onthe prime carrier 601. The control format indicator 701 may indicate anumber of OFDM symbols in the first subframe 708 employed fortransmission of downlink control information on a second control channel702 on the first subframe 708 of the prime carrier 601.

The base station may transmit downlink control information on the secondcontrol channel 702 on the prime carrier 601. The second control channel702 may provide transmission format and scheduling information for afirst plurality of data packets transmitted on a first data channel 703of the prime carrier 601. Downlink control information on the secondcontrol channel 702 may be transmitted on the prime carrier 601 startingfrom the first OFDM symbol of the subframe 708. A subset of OFDMsubcarriers of the first symbol of the subframe may be employed for thefirst control channel transmission, and a second subset of OFDMsubcarriers of the first symbol of the subframe may be employed for thesecond control channel transmission.

The base station may transmit the first plurality of data packets on thefirst data channel 703. Transmission of the first plurality of datapackets on the first data channel may start from the OFDM symbolsubsequent to the number of OFDM symbols employed for transmission ofthe downlink control information on the second control channel 702. Forexample in a given subframe, the first, second and third symbols may beemployed for transmission of the first and second control channel, andthe fourth to fourteenth symbols may be employed for transmission of thefirst data channel.

According to some of the various aspects of embodiments, downlinkcontrol information may be transmitted on a physical control channel 702on the prime carrier 601. The base station may transmit at least onecontrol message on the first data channel 703. The at least one controlmessage may be configured to cause configuration of a non-prime carrier602 in a wireless device. The at least one control message may comprisethe configuration of radio resources of the non-prime carrier comprisinga second data channel. In a first carrier configuration, the controlchannel 702 may be configured to provide transmission format andscheduling information for the first plurality of data packetstransmitted on the prime carrier 601 and the second plurality of datapackets transmitted on the non-prime carrier 602. The control channel602 may be transmitted on the prime carrier 601 starting from the firstOFDM symbol of a subframe. The control channel may be a physicaldownlink control channel. No physical control format indicator channels,no physical downlink HARQ indicator channel, and no physical downlinkcontrol channels may be transmitted on the non-prime carrier 602. Thenon-prime carrier 602 may be configured to operate without transmittingphysical control format indicator channel, physical downlink HARQindicator channel, and physical downlink control channel. Radioresources of the second data channel 705 may be configured to start fromthe first OFDM symbol of a subframe 708 of the non-prime carrier 602 andto end at the last OFDM symbol of the subframe of the non-prime carrier602. No HARQ feedback may be transmitted on the non-prime carrier 602.The non-prime carrier 602 may be configured to operate withouttransmitting HARQ feedback on the non-prime carrier 602.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina second carrier configuration, the control channel 702 may beconfigured to provide transmission format and scheduling information forthe first plurality of data packets transmitted on the prime carrier601. The control channel 702 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe 708. The controlchannel may be a physical downlink control channel. Second controlinformation may be transmitted on a second control channel 711 on thenon-prime carrier 602. The second control channel 711 may be configuredto provide transmission format and scheduling information for the secondplurality of data packets transmitted on the non-prime carrier 602. Thesecond control channel may be an enhanced physical downlink controlchannel. Radio resources of the second data channel 705 may beconfigured to start from the first OFDM symbol of a subframe of thenon-prime carrier 602 and end at the last OFDM symbol of the subframe ofthe non-prime carrier 602.

In an example embodiment, downlink control information may betransmitted on a physical control channel 702 on the prime carrier 601.The base station may transmit at least one control message on the firstdata channel 703. The at least one control message may be configured tocause configuration of a non-prime carrier 602 in a wireless device. Theat least one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina third carrier configuration, the control channel 702 may be configuredto provide transmission format and scheduling information for the firstplurality of data packets transmitted on the prime carrier 601 and thesecond plurality of data packets transmitted on the non-prime carrier602. The control channel 602 may be transmitted on the prime carrier 601starting from the first OFDM symbol of a subframe. The control channelmay be a physical downlink control channel. No physical control formatindicator channels, no physical downlink HARQ indicator channel, and nophysical downlink control channels may be transmitted on the non-primecarrier 602. The non-prime carrier 602 may be configured to operatewithout transmitting physical control format indicator channel, physicaldownlink HARQ indicator channel, and physical downlink control channel.No HARQ feedback may be transmitted on the non-prime carrier 602. Thenon-prime carrier 602 may be configured to operate without transmittingHARQ feedback on the non-prime carrier 602. The starting symbol of radioresources of the second physical downlink shared channel 705 may beindicated by at least one control message. For example, the startingsymbol of the second physical downlink shared channel 705 may beconfigured to start from the third symbol of a subframe. In thisconfiguration, the first and second symbol of the subframe may not beemployed for transmission of control and data channels. The base stationmay transmit substantially reduced power or no power in the first twosymbols of the subframe. In an implementation option, the ending symbolof the second physical downlink shared channel 705 may be indicated byat least one control message.

According to some of the various aspects of embodiments, downlinkcontrol information may be transmitted on a physical control channel 702on the prime carrier 601. The base station may transmit at least onecontrol message on the first data channel 703. The at least one controlmessage may be configured to cause configuration of a non-prime carrier602 in a wireless device. The at least one control message may comprisethe configuration of radio resources of the non-prime carrier comprisinga second data channel. In a fourth carrier configuration, the controlchannel 702 may be configured to provide transmission format andscheduling information for the first plurality of data packetstransmitted on the prime carrier 601. The control channel 702 may betransmitted on the prime carrier 601 starting from the first OFDM symbolof a subframe 708. The control channel may be a physical downlinkcontrol channel. Second control information may be transmitted on asecond control channel 711 on the non-prime carrier 602. The secondcontrol channel 711 may be configured to provide transmission format andscheduling information for the second plurality of data packetstransmitted on the non-prime carrier 602. The second control channel maybe an enhanced physical downlink control channel. The starting symbol ofradio resources of the second physical downlink shared channel 705and/or the second control channel 711 may be indicated by at least onecontrol message. For example, the starting symbol of the second physicaldownlink shared channel 705 and/or the second control channel 711 may beconfigured to start from the third symbol of a subframe. In thisconfiguration, the first and second symbol of the subframe may not beemployed for transmission of control and data channels. The base stationmay transmit substantially reduced power or no power in the first twosymbols of the subframe. In an implementation option, the ending symbolof the second physical downlink shared channel 705 and/or the secondcontrol channel 711 may be indicated by at least one control message.

The control format indicator on the first control channel 701 may betransmitted on a first subset of the plurality of OFDM subcarriers ofthe prime carrier 601. An instance of the first control channel maytransmit a control format indicator 601 and may indicate one of threepossible values after being decoded. The range of possible values of acontrol format indicator may depend on at least one parameter. The atleast one parameter may comprise the prime carrier bandwidth. Forexample for a given bandwidth, the first control channel may indicateone of three possible values of 1, 2, or 3 symbols. The first controlchannel 701 may be transmitted on the first OFDM symbol of a subframe708 of the prime carrier 601 using QPSK modulation. The first controlchannel 701 may be encoded using a block encoder before transmission.The first control channel 701 may be scrambled by a transmitter IDbefore transmission. The transmitter ID may be, for example, thephysical cell ID.

According to some of the various aspects of embodiments, the downlinkcontrol information on the second control channel 702 may be transmittedon a second subset of the plurality of OFDM subcarriers of the primecarrier 601. The downlink control information on the second controlchannel 702 may be transmitted using QPSK modulated symbols. Thedownlink control information on the second control channel 702 may beencoded by a tail biting convolutional encoder before transmission. Thesecond control channel 702 may further provide power control commandsfor at least one uplink channel (e.g. power control commands for aphysical uplink shared channel and/or physical uplink control channel).The OFDM subcarriers of radio resources that are employed fortransmission of the second control channel 702 may occupy the entireactive bandwidth of the prime carrier 601. The control data transmittedon the second channel may not employ the entire subcarriers allocated tothe control channel. The second control channel 702 may carry aplurality of downlink control packets in a subframe 708. The pluralityof downlink control packets may be scrambled employing a radio networkidentifier.

According to some of the various aspects of embodiments, PDCCH 702 maybe configured for a prime carrier 601, and enhanced PDCCH 711 may beconfigured for a non-prime carrier 602. As shown in FIG. 7, radioresources employed by PDCCH may span the entire active prime carrierbandwidth in frequency and may occupy one, two, three or four symbols ofa subframe. PCFICH 701 transmitted in a plurality of OFDM subcarriers ofthe first symbol of the subframe may identify the duration of the PDCCHin the subframe. Radio resources employed for PDSCH may span the entireactive prime carrier bandwidth in frequency and may start from thesymbol subsequent to the last symbol employed for PDCCH and end at thelast symbol of the subframe. If synchronization signal and PBCH aretransmitted in a subframe, PDSCH resources may exclude the resourceblocks 709 employed by synchronization signal and PBCH in the subframe.A subset of OFDM symbols 710, 714 in the first symbol, or subset of OFDMsymbols in the first, second and third symbols of a subframe may beemployed for downlink PHICH transmission. The active bandwidth of acarrier comprise the active subcarriers and my not include nullsubcarriers such as guard subcarriers. A control packet transmitted onPDCCH may employ a subset of resources allocated to PDCCH. A packettransmitted on PDSCH may employ a subset of resources allocated toPDSCH.

As shown in FIG. 7, radio resources employed by enhanced PDCCH may beconfigured to span in a limited number of configured resource blocksstarting from an offset frequency configured in terms of the resourceblocks. PCFICH may not be transmitted on a non-prime carrier, andenhanced PDCCH configuration may be transmitted to the wireless devicevia RRC messages transmitted on a prime carrier. Radio resourcesemployed for PDSCH may span the entire active prime carrier bandwidth infrequency excluding the resource blocks employed by enhanced PDCCH. Inan example embodiment, if synchronization signal and/or PBCH aretransmitted in a subframe, PDSCH resources may exclude the resourceblocks 712 employed by synchronization signal and/or PBCH in thesubframe. In an example embodiment, enhanced PDCCH 711 and PDSCH 705radio resources may start from the first symbol of a subframe and end atthe last symbol of the subframe. Enhanced PDCCH 711 and PDSCH 705 radioresources may span the entire duration of a subframe in time. In anotherexample implementation, the starting symbol and/or the ending symbol ofenhanced PDCCH and PDSCH in all or a subset of subframes may be aconfigurable parameter and may be indicated to a wireless deviceemploying RRC signaling. In an example implementation, some of theresource elements of resource blocks employed for enhanced PDCCH may beemployed for an enhanced PHICH transmission. Enhanced PHICH may carryack/nack for uplink packets transmitted on the non-prime uplink carrier.A control packet transmitted on enhanced PDCCH may employ a subset ofresources allocated to enhanced PDCCH. A packet transmitted on PDSCH mayemploy a subset of resources allocated to PDSCH.

The first plurality of data packets and the second plurality of datapackets may be encrypted packets. The first plurality of data packetsand the second plurality of data packets may be assigned to a radiobearer. A first plurality of packets that are assigned to the same radiobearer may be encrypted using an encryption key and at least oneparameter that changes substantially rapidly over time. An example ofthe parameter that changes substantially rapidly over time may be acounter, for example, a packet sequence number.

RRC messages may be encrypted and may be protected by an integrityheader before it is transmitted. The at least one control message may betransmitted by an RRC protocol module. The at least one control messagemay further comprise configuration information for physical channels fora wireless device. The at least one control message may set up or modifyat least one radio bearer. The at least one control message may modifyconfiguration of at least one parameter of a MAC layer or a physicallayer. The at least one control message may be an RRC connectionreconfiguration message.

The transmission and reception mechanisms in the example embodiments mayincrease bandwidth efficiency in the system. The proposed transmissionand reception mechanisms may provide a set of constraints for assigningwireless physical resources to data and control packet transmission thatmay result in increased overall air interface capacity. The non-primecarrier may be employed to provide additional capacity. In the exampleembodiments, the non-prime carrier may not carry some of the physicalchannels that are required, for example, in LTE release 8, 9 and 10.This may improve wireless interface spectral efficiency.

In an example embodiment of the invention implemented in an LTE network,the first control channel may be a physical control format indicatorchannel (PCFICH), the second control channel may be a physical downlinkcontrol channel (PDCCH), and the first and second data channels may bethe first and second physical downlink shared channels (PDSCH). DownlinkHARQ feedback may be transmitted employing a physical HARQ indicatorchannel (PHICH), and the physical broadcast channel may comprise atleast one information field related to system information.

According to some of the various aspects of embodiments, PCFICH, PDCCH,PBCH, BCCH, and/or PCH may be transmitted on the prime carrier. Thenon-prime carrier may be configured to operate without transmittingPCFICH, PDCCH, PBCH, BCCH and/or PCH in any subframe. PDCCH transmittedon the prime carrier may transmit scheduling packets for the first andsecond PDSCH. An example embodiment may eliminate PCFICH and PDCCHtransmission on the non-prime carrier and release the capacity thatshould have been used for these control channels to PDSCH. This mayincrease the data capacity of the second carrier, and may increase thespectral efficiency of the system. In an example embodiment, a carrierin the plurality of carriers may be classified as a prime carrier or anon-prime carrier, wherein the transmitter transmits at least one primecarrier and at least one non-prime carrier. The prime carriers maytransmit PCFICH, PDCCH, PBCH, BCCH, PCH channels, and/or the like. Thenon-prime carriers may be configured to operate without transmitting thePCFICH, PDCCH, SS, PBCH, BCCH, PCH channels, and/or the like. Thescheduling packets corresponding to data packets transmitted onnon-prime carriers may be transmitted in PDCCH channels of one of theprime carriers. The resources allocated to the data channel in non-primecarriers may start from the first symbol of a subframe.

According to some of the various aspects of embodiments, a wirelessdevice may receive from a base station a synchronization signal 615,606, 608, 609 comprising a primary synchronization signal 606, 609 and asecondary synchronization signal 615, 608 on the prime carrier 601. Thesynchronization signal may indicate a physical cell ID for a cellcomprising the prime carrier 601. The synchronization signal may alsoprovide timing information for the prime carrier 601 and/or thenon-prime carrier 602 in the plurality of carriers. The synchronizationsignal may be received employing a plurality of subcarrierssubstantially in the center of the frequency band of the prime carrier601 on the first and sixth subframes (subframe 0 and 5) of each frame inthe plurality of frames. Primary and secondary synchronization signalsmay occupy a bandwidth of approximately six resource blocks. Thewireless device may receive physical broadcast channel (PBCH) 607 inslot one 604 of subframe 0 of the prime carrier 301. The wireless devicemay receive the synchronization signals to obtain and/or track carrierframe and subframe timing. The wireless device may receive PBCH signalto obtain at least one configuration parameter of the downlink carrier.

According to some of the various aspects of embodiments, a wirelessdevice may receive from a base station a synchronization signal 615,606, 608, 609 comprising a primary synchronization signal 606, 609 and asecondary synchronization signal 615, 608 on the prime carrier 601. Thesynchronization signal may indicate a physical cell ID for a cellcomprising the prime carrier 601. The synchronization signal may alsoprovide timing information for the prime carrier 601 and the non-primecarrier 602 in the plurality of carriers. The synchronization signal maybe received employing a plurality of subcarriers substantially in thecenter of the frequency band of the prime carrier 601 on the first andsixth subframes (subframe 0 and 5) of each frame in the plurality offrames. Primary and secondary synchronization signals may occupy abandwidth equal to six resource blocks. The wireless device may receivea physical broadcast channel (PBCH) 607 in slot one 604 of subframe 0 ofthe prime carrier 301. In one example embodiment, radio resources 610,611, 612, 613 and 614 may not be employed for reception of asynchronization signal and PBCH. These resources may be employed forreceiving data on the downlink carrier. For example, these radioresources may be employed for reception of data packets on a non-primecarrier physical downlink shared channel.

According to some of the various aspects of embodiments, a wirelessdevice may receive a first synchronization signal 615, 606, 608, 609comprising a primary synchronization signal 606, 609 and a secondarysynchronization signal 615, 608 on the prime carrier 601. The firstsynchronization signal may indicate a physical cell ID for a cellcomprising the prime carrier 601. The first synchronization signal mayprovide timing information for the prime carrier 601. A secondsynchronization signal may be received on the non-prime carrier. Thesecond synchronization signal may be received employing a plurality ofsubcarriers substantially in the center of the frequency band of thenon-prime carrier 602 employing six resource blocks. A secondsynchronization signal may comprise a second primary synchronizationsignal and a second secondary synchronization signal. In an exampleembodiment, the second synchronization signal may be received on asecond time location (different from time location of the firstsynchronization signal) in the same or different subframe compared withthe first synchronization signal. The second synchronization signal mayprovide timing information for the non-prime carrier 602.

The wireless device may receive from the base station a first pluralityof data packets on a first data channel 703 of the prime carrier 601 ona first plurality of OFDM subcarriers. A first plurality of OFDMsubcarriers may exclude a plurality of subcarriers used for transmissionof the primary 606, 609 and secondary 615, 608 synchronization signalsin the first and sixth subframes in the plurality of frames. A firstplurality of OFDM subcarriers may exclude a plurality of subcarriersused for transmission of the PBCH 607. PSS/SSS/PBCH resources 709 on theprime carrier 601 in an example subframe 708 are illustrated in FIG. 7.

The wireless device may receive from the base station a first pluralityof broadcast system information messages (SIB messages) on the firstdata channel 703 employing, for example, radio resources 704. Theplurality of broadcast system information messages may comprise aplurality of radio link configuration parameters of the prime carrier601 for the wireless device receiving the prime carrier 601 and thenon-prime carrier 602 signals. An example radio resource 704 employedfor SIB message transmission is illustrated in FIG. 7. SIB messages maybe received continuously and may be received on a subset of the downlinksubframes of the prime carrier 601. System information of the non-primecarrier 602 may be received via at least one unicast RRC message whenthe non-prime carrier 602 is configured by higher layers. In an exampleembodiment, the at least one unicast RRC message may be received on thefirst data channel 703 of the prime carrier 601. The non-prime carrier602 may be configured to operate without broadcasting the systeminformation blocks on the non-prime carrier 602. The wireless device mayreceive a second plurality of data packets on a second data channel 705on a second plurality of OFDM subcarriers of the non-prime carrier 602.

According to some of the various aspects of embodiments, the secondplurality of OFDM subcarriers of the non-prime carrier 602 may comprisethe OFDM subcarriers substantially in the center of the frequency bandat symbols 610, 611, 613, and 614 of the non-prime carrier 602 in thefirst and sixth subframes in the plurality of frames. No primarysynchronization signal and no secondary synchronization signal may bereceived on the second carrier in radio resource 610, 611, 613, and 614.The non-prime carrier may be configured to operate without receivingprimary synchronization signal and secondary synchronization signal inradio resource 610, 611, 613, and 614. No broadcast system informationmessage (SIB messages) may be received on the second data channel 705.The non-prime carrier 602 may be configured to operate without receivingsystem information message (SIB messages). No physical broadcast channelmay be received in radio resource 612. The non-prime carrier 602 may beconfigured to operate without receiving physical broadcast channel inradio resource 612. In an example embodiment, if non-prime carrier 602is a synchronized non-prime carrier, subframe timing of the non-primecarrier 602 may be provided by the synchronization signal received onthe prime carrier 601. In another example embodiment, if the non-primecarrier 602 is an unsynchronized non-prime carrier, subframe timing ofthe non-prime carrier 602 may be provided by a second synchronizationsignal received on the non-prime carrier 602. In an example embodiment,if synchronization signals are received on a non-prime carrier 602,radio resources 712 of synchronization signal may be in a different timelocation in the same subframe 708 (as shown in FIG. 7) or in a differentsubframe (not shown in FIG. 7). The first plurality of data packets andthe second plurality of data packets may be received using a pluralityof physical resource blocks.

In an example embodiment, downlink control information may be receivedon a physical control channel 702 on the prime carrier 601. The wirelessdevice may receive from the base station at least one control message onthe first data channel 703. The at least one control message may beconfigured to cause configuration of a non-prime carrier 602 in thewireless device. The at least one control message may comprise theconfiguration of radio resources of the non-prime carrier comprising asecond data channel. In a first carrier configuration, the controlchannel 702 may be configured to provide transmission format andscheduling information for the first plurality of data packets receivedon the prime carrier 601 and the second plurality of data packetsreceived on the non-prime carrier 602. The control channel 602 may bereceived on the prime carrier 601 starting from the first OFDM symbol ofa subframe. The control channel may be a physical downlink controlchannel. No physical control format indicator channels, no physicaldownlink HARQ indicator channel, and no physical downlink controlchannels may be received on the non-prime carrier 602. The non-primecarrier 602 may be configured to operate without received physicalcontrol format indicator channel, physical downlink HARQ indicatorchannel, and physical downlink control channel. Radio resources of thesecond data channel 705 may be configured to start from the first OFDMsymbol of a subframe 708 of the non-prime carrier 602 and to end at thelast OFDM symbol of the subframe of the non-prime carrier 602. No HARQfeedback may be received on the non-prime carrier 602. The non-primecarrier 602 may be configured to operate without receiving HARQ feedbackon the non-prime carrier 602.

FIG. 9 is a diagram depicting example control and data reception for aprime downlink carrier 601, a non-prime downlink carrier 602, a primeuplink carrier 811, and a non-prime uplink carrier 812 as per an aspectof an embodiment of the present invention. Downlink subframe 903 may notbe received at the same time with uplink subframe 904. Radio resources905 are employed for reception of PCFICH, PDCCH, and PHICH. The downlinkcontrol channel (PDCCH) in radio resources 905 may be configured toprovide reception format and scheduling information for a firstplurality of packets received on a first downlink shared channel 906, asecond plurality of packets received on a second downlink shared channel907, a third plurality of data packets received on a first uplink sharedchannel 908, and a fourth plurality of data packets received on a seconduplink shared channel 909. For example control packet 916 may providereception format and scheduling information for data packet 913. Controlpacket 922 may provide reception format and scheduling information fordata packet 933. Control packet 918 may provide reception format andscheduling information for data packet 914. Control packet 920 mayprovide reception format and scheduling information for data packet 924.Control packets 918 and 920 may also comprise power control informationfor transmission of packets 914 and 924 respectively. The prime uplinkcarrier 811 may comprise: a) a first portion of bandwidth employed forthe first uplink data channel 908; and b) a second portion of thebandwidth employed for a first uplink control channel 910.

In an example embodiment, downlink control information may be receivedon a physical control channel 702 on the prime carrier 601. The wirelessdevice may receive at least one control message on the first datachannel 703. The at least one control message may be configured to causeconfiguration of a non-prime carrier 602 in the wireless device. The atleast one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina second carrier configuration, the control channel 702 may beconfigured to provide transmission format and scheduling information forthe first plurality of data packets received on the prime carrier 601.The control channel 702 may be received on the prime carrier 601starting from the first OFDM symbol of a subframe 708. The controlchannel may be a physical downlink control channel. Second controlinformation may be received on a second control channel 711 on thenon-prime carrier 602. The second control channel 711 may be configuredto provide transmission format and scheduling information for the secondplurality of data packets received on the non-prime carrier 602. Thesecond control channel may be an enhanced physical downlink controlchannel. Radio resources of the second data channel 705 may beconfigured to start from the first OFDM symbol of a subframe of thenon-prime carrier 602 and end at the last OFDM symbol of the subframe ofthe non-prime carrier 602.

FIG. 8 is a diagram depicting example control and data transmission fora prime downlink carrier 601, a non-prime downlink carrier 602, a primeuplink carrier 811, and a non-prime uplink carrier 812 as per an aspectof an embodiment of the present invention. Downlink subframe 803 may notbe received at the same time with uplink subframe 804. Radio resources805 are employed for reception of PCFICH, PDCCH, and PHICH. The downlinkcontrol channel (PDCCH) in radio resources 805 may be configured toprovide transmission format and scheduling information for a firstplurality of packets received on a first downlink shared channel 806,and a third plurality of data packets received on a first uplink sharedchannel 808. Enhance control channel 824 may be configured to providetransmission format and scheduling information for a second plurality ofpackets received on a second downlink shared channel 807, and a fourthplurality of data packets received on a second uplink shared channel809. For example control packet 814 may provide transmission format andscheduling information for data packet 820. Control packet 816 mayprovide transmission format and scheduling information for data packet830. Control packet 926 may provide transmission format and schedulinginformation for data packet 818. Control packet 928 may providetransmission format and scheduling information for data packet 832.Control packets 816 and 928 may also comprise power control informationfor transmission of packets 830 and 832 respectively. The prime uplinkcarrier 811 may comprise: a) a first portion of bandwidth employed forthe first uplink data channel 808; and b) a second portion of thebandwidth employed for a first uplink control channel 810.

In an example embodiment, downlink control information may be receivedon a physical control channel 702 on the prime carrier 601. The wirelessdevice may receive at least one control message on the first datachannel 703. The at least one control message may be configured to causeconfiguration of a non-prime carrier 602 in the wireless device. The atleast one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina third carrier configuration, the control channel 702 may be configuredto provide transmission format and scheduling information for the firstplurality of data packets received on the prime carrier 601 and thesecond plurality of data packets received on the non-prime carrier 602.The control channel 602 may be received on the prime carrier 601starting from the first OFDM symbol of a subframe. The control channelmay be a physical downlink control channel. No physical control formatindicator channels, no physical downlink HARQ indicator channel, and nophysical downlink control channels may be received on the non-primecarrier 602. The non-prime carrier 602 may be configured to operatewithout receiving physical control format indicator channel, physicaldownlink HARQ indicator channel, and physical downlink control channel.No HARQ feedback may be received on the non-prime carrier 602. Thenon-prime carrier 602 may be configured to operate without receivingHARQ feedback on the non-prime carrier 602. The starting symbol of radioresources of the second physical downlink shared channel 705 may beindicated by at least one control message. For example, the startingsymbol of the second physical downlink shared channel 705 may beconfigured to start from the third symbol of a subframe. In thisconfiguration, the first and second symbol of the subframe may not beemployed for reception of control and data channels. The base stationmay transmit substantially reduced power or no power in the first twosymbols of the subframe. In an implementation option, the ending symbolof the second physical downlink shared channel 705 may be indicated byat least one control message.

In an example embodiment, downlink control information may be receivedon a physical control channel 702 on the prime carrier 601. The basestation may receive at least one control message on the first datachannel 703. The at least one control message may be configured to causeconfiguration of a non-prime carrier 602 in the wireless device. The atleast one control message may comprise the configuration of radioresources of the non-prime carrier comprising a second data channel. Ina fourth carrier configuration, the control channel 702 may beconfigured to provide transmission format and scheduling information forthe first plurality of data packets received on the prime carrier 601.The control channel 702 may be received on the prime carrier 601starting from the first OFDM symbol of a subframe 708. The controlchannel may be a physical downlink control channel. Second controlinformation may be received on a second control channel 711 on thenon-prime carrier 602. The second control channel 711 may be configuredto provide transmission format and scheduling information for the secondplurality of data packets transmitted on the non-prime carrier 602. Thesecond control channel may be an enhanced physical downlink controlchannel. The starting symbol of radio resources of the second physicaldownlink shared channel 705 and/or the second control channel 711 may beindicated by at least one control message. For example, the startingsymbol of the second physical downlink shared channel 705 and/or thesecond control channel 711 may be configured to start from the thirdsymbol of a subframe. In this configuration, the first and second symbolof the subframe may not be employed for reception of control and datachannels. The base station may transmit substantially reduced power orno power in the first two symbols of the subframe. In an implementationoption, the ending symbol of the second physical downlink shared channel705 and/or the second control channel 711 may be indicated by at leastone control message.

Radio resources 709 may be configured to provide a synchronizationsignal on the prime carrier 601. In an example carrier configuration, ifthe non-prime carrier is configured to carry a synchronization signal,radio resources 712 may be configured to provide the secondsynchronization signal on the non-prime carrier. In another exampleembodiment, the non-prime carrier may be configured to operate withoutreceiving the second synchronization signal. In that case, the wirelessdevice may employ the synchronization signal 709 received on the primecarrier 601 for frame and subframe timing of the prime carrier 601 andthe non-prime carrier 602.

FIG. 7 is a diagram illustrating synchronization, data and controltransmission channels as per an aspect of an embodiment of the presentinvention. The wireless device may receive first control information ona first control channel on the first OFDM symbol of subframes of a primecarrier 601 in the plurality of carriers. An instance of the firstcontrol channel information may comprise a control format indicator. Thewireless device may receive a plurality of control format indicators onthe first control channel. A control format indicator 701 in theplurality of control format indicators may be received on the firstcontrol channel over the first OFDM symbol in a plurality of OFDMsymbols of the first subframe 708 in a plurality of subframes. The firstcontrol channel may be received in all subframes of the prime carrier601 (when wireless device is active for reading the subframe). Theplurality of control format indicators may be received on the primecarrier 601. The control format indicator 701 may indicate a number ofOFDM symbols in the first subframe 708 employed for reception ofdownlink control information on a second control channel 702 on thefirst subframe 708 of the prime carrier 601.

The wireless device may receive downlink control information on thesecond control channel 702 on the prime carrier 601. The second controlchannel 702 may provide transmission format and scheduling informationfor a first plurality of data packets received on a first data channel703 of the prime carrier 601. Downlink control information on the secondcontrol channel 702 may be received on the prime carrier 601 startingfrom the first OFDM symbol of the subframe 708. A subset of OFDMsubcarriers of the first symbol of the subframe may be employed for thefirst control channel reception, and a second subset of OFDM subcarriersof the first symbol of the subframe may be employed for the secondcontrol channel reception.

Legacy release 8 and 9 LTE wireless devices may be able to connect to aprime carrier 601. Legacy release 8 and 9 LTE wireless devices may notbe able to connect to non-prime carriers. Wireless devices employing anexample embodiment may be able to connect to a prime carrier 601, andthen employ a non-prime carrier 602 to further enhance the datatransmission rate. The initial connection may be set up employing aprime carrier. A wireless device may receive a paging message on a primecarrier. A wireless device may start a random access procedure in theuplink carrier corresponding to a prime downlink carrier to establish aconnection. Signaling radio bearer one in LTE may be established using aprime downlink carrier and a corresponding prime uplink carrier. Thewireless device may establish other signaling and data radio bearers ona prime carrier, a non-prime carrier, and/or both.

According to some of the various aspects of embodiments, a base stationmay be configured to communicate employing a plurality of carriers. Thebase station may transmit at least one control message to a wirelessdevice. The at least one control message may be configured to causeconfiguration of a plurality of carriers. The plurality of carriers maycomprise at least one prime carrier and at least one non-prime carrier.A prime carrier and/or a non-prime carrier may comprise a plurality ofsubcarriers. Transmission time may be divided into a plurality offrames. A frame may be assigned a system frame number represented by mbits. A frame may be divided into a plurality of subframes. The basestation comprises at least one communication interface, at least oneprocessor, and memory. The memory stores instructions that, whenexecuted, cause the transmitter to perform the required functions. Thebase station may transmit in a frame in the sequential series of frameson a prime carrier the n most significant bits of a system frame number.The base station may transmit the n most significant bits of a systemframe number employing a plurality of subcarriers substantially in thecenter of the frequency band of the prime carrier on the first subframeof the frame in an information element in a control block transmitted ona physical broadcast channel. Each frame in the sequential series offrames may be assigned a system frame number. The system frame numbermay be represented by m bits.

The base station may transmit the (m−n) least significant bits of thesystem frame number implicitly by encoding control blocks in thephysical broadcast channel over 2̂(m−n) frames (2 to the power of m−n).Sequential position of the encoded control blocks may determine the(m−n) least significant bits. In other word, the timing of the encodedcontrol blocks on the physical broadcast channel may determine the m−nleast significant bits. The base station may transmit the same systemframe number in frames of the at least one prime carrier if the framesare transmitted at the same time.

The base station may transmit and receive, by employing a communicationinterface, a first plurality of packets in the frame on a prime carrier.The communication interface may employ, at least in part, the systemframe number transmitted in the frame of the prime carrier. The primecarrier may be configured to operate broadcasting the system framenumber on the prime carrier.

The base station may transmit and receive, by employing a communicationinterface, a second plurality of packets in the frame on a non-primecarrier. The communication interface may employ, at least in part, thesystem frame number transmitted in the frame of the prime carrier. Thenon-prime carrier may be configured to operate without broadcasting thesystem frame number on the non-prime carrier.

A first of category of wireless devices may be configured to receive theat least one prime carrier, and are unable to receive a non-primecarrier. A second category of wireless devices may be configured toreceive the at least one prime carrier and the at least one non-primecarrier. A prime carrier in the at least one prime carrier may have alarger coverage area than a non-prime carriers in the at least onenon-prime carrier. The physical broadcast channel transmitted on a primecarrier comprises downlink bandwidth, system frame number, and/or PHICHconfiguration of the prime carrier. In an example embodiment, n may beequal to 8, and m may be equal to 10.

The base station may scramble the control blocks transmitted on thephysical broadcast channel with a cell-specific sequence prior tomodulation. The base station may modulate the control blocks transmittedon the physical broadcast channel using QPSK modulation. The basestation may encode the control blocks transmitted on the physicalbroadcast channel employing tail biting convolutional coding beforetransmission. The base station may add CRC bits to an encoded controlblock of the physical broadcast channel before transmission. The CRCbits are scrambled according to the base station transmit antennaconfiguration. The base station may transmit a plurality of controlpackets on the second data channel. Integrity checksum may be calculatedfor the plurality of control packets using a plurality of parameterscomprising a hyper frame number. The integrity checksum may be appendedto the plurality of control packets before transmission.

A base station may be configured to communicate employing a plurality ofcarriers. The base station may transmit at least one control message toa wireless device. The at least one control message may be configured tocause configuration of the plurality of carriers. The plurality ofcarriers configured to transmit symbols in a sequential series offrames. The plurality of carriers may comprise at least one primecarrier and at least one non-prime carrier. The base station maytransmit a system frame number in a physical broadcast channel in aframe in the sequential series of frames on a prime carrier in the atleast one prime carrier. The base station may transmit and receive, byemploying a communication interface, a second plurality of packets inthe frame on a non-prime carrier in the at least one non-prime carrier.The communication interface may employ, at least in part, the systemframe number transmitted in the frame of the prime carrier. Thenon-prime carrier is configured to operate without broadcasting thesystem frame number on the non-prime carrier.

According to some of the various aspects of embodiments, a wirelessdevice may be configured to communicate employing a plurality ofcarriers. The wireless device may receive at least one control messagefrom a base station. The at least one control message may be configuredto cause configuration of a plurality of carriers. The plurality ofcarriers may comprise at least one prime carrier and at least onenon-prime carrier. A prime carrier and/or a non-prime carrier maycomprise a plurality of subcarriers. Reception time may be divided intoa plurality of frames. A frame may be assigned a system frame numberrepresented by m bits. A frame may be divided into a plurality ofsubframes. The wireless device comprises at least one communicationinterface, at least one processor, and memory. The memory storesinstructions that, when executed, cause the transmitter to perform therequired functions. The wireless device may receive in a frame in thesequential series of frames on a prime carrier the n most significantbits of a system frame number. The wireless device may receive the nmost significant bits of a system frame number employing a plurality ofsubcarriers substantially in the center of the frequency band of theprime carrier on the first subframe of the frame in an informationelement in a control block transmitted on a physical broadcast channel.Each frame in the sequential series of frames may be assigned a systemframe number. The system frame number may be represented by m bits.

The wireless device may receive the (m−n) least significant bits of thesystem frame number implicitly by decoding control blocks in thephysical broadcast channel over 2̂(m−n) frames (2 to the power of m−n).Sequential position of the encoded control blocks may determine the(m−n) least significant bits. In other word, the timing of the encodedcontrol blocks on the physical broadcast channel may determine the m−nleast significant bits. The wireless device may receive the same systemframe number in frames of the at least one prime carrier if the framesare received at the same time.

The wireless device may transmit and receive, by employing acommunication interface, a first plurality of packets in the frame on aprime carrier. The communication interface may employ, at least in part,the system frame number received in the frame of the prime carrier. Theprime carrier may be configured to operate receiving the system framenumber on the prime carrier.

The wireless device may transmit and receive, by employing acommunication interface, a second plurality of packets in the frame on anon-prime carrier. The communication interface may employ, at least inpart, the system frame number received in the frame of the primecarrier. The non-prime carrier may be configured to operate withoutreceiving the system frame number on the non-prime carrier.

The physical broadcast channel received on a prime carrier may comprisedownlink bandwidth, system frame number, and/or PHICH configuration ofthe prime carrier. In an example embodiment, n may be equal to 8, and mmay be equal to 10.

The wireless device may descramble the control blocks received on thephysical broadcast channel with a cell-specific sequence prior tomodulation. The wireless device may demodulate the control blocksreceived on the physical broadcast channel using QPSK modulation. Thewireless device may decode the control blocks transmitted on thephysical broadcast channel employing tail biting convolutional decoding.The receiver may remove CRC bits from a decoded control block of thephysical broadcast channel. The CRC bits may be descrambled according tothe base station transmit antenna configuration. The wireless device mayreceive a plurality of control packets on the second data channel.Integrity checksum may be calculated for the plurality of controlpackets using a plurality of parameters comprising a hyper frame number.

According to some of the various aspects of embodiments, downlinkassignments transmitted on the PDCCH may indicate if there is atransmission on a downlink shared channel for a particular wirelessdevice and/or may provide the relevant hybrid ARQ information. Forconfigured downlink assignments, the hybrid ARQ process identifierassociated with the subframe may be derived, at least in part, as afunction of transmission time interval number. The transmission timeinterval number may be derived as (system frame number×10)+subframenumber. When a wireless device needs to read broadcast control channel,the wireless device may employ the system frame number for decoding.

In an example configuration and when certain condition are met, thewireless device may determine the redundancy version of the receiveddownlink assignment for this transmission time interval, at least inpart, as a function of system frame number and other radio configurationvariables. For example, the wireless device, based on the schedulinginformation from RRC, and if a downlink assignment for this transmissiontime interval has been received on the PDCCH of the primary cell for thesystem information blocks, and if the redundancy version is not definedin the PDCCH format: the wireless device may determine the redundancyversion of the received downlink assignment for this transmission timeinterval, at least in part, as a function of system frame number and/orat least one other radio configuration variable. The encoding (forexample redundancy version) in the base station may also be based, atleast in part, on system frame number. If the redundancy version isdefined in the PDCCH format, wireless device may indicate a downlinkassignment and redundancy version for the dedicated broadcast hybrid ARQprocess to the hybrid ARQ entity for this transmission time interval.

According to some of the various aspects of embodiments, the wirelessdevice may be configured by RRC with a discontinuous receptionfunctionality that controls the wireless device's PDCCH monitoringactivity for the least wireless device radio network temporaryidentifier. The base station may consider wireless device discontinuousreception timing, when base station transmits a scheduling controlpacket to a wireless device. When wireless device is in connected mode,and when discontinuous reception is configured, the wireless device maybe allowed to monitor the PDCCH discontinuously, otherwise the wirelessdevice may monitor the PDCCH continuously. Wireless device may receivediscontinuous reception configuration parameters from the base stationemploying RRC messages. The discontinuous reception is configured, thewireless device may employ, at least in part, the discontinuousreception configuration parameters and the system frame number todetermine in which subframe the wireless device may read the PDCCH.

In a downlink carrier and/or uplink carrier, after a semi-persistentdownlink assignment is configured, the wireless device may consider thatthe assignment recurs in subframes for which (10× system framenumber+subframe number) transmission time interval number,semi-persistent scheduling resources are allocated. The assignment maystart at a system frame number start number and subframe number startnumber, and according to semi-persistent resource assignmentconfiguration.

According to some of the various aspects of embodiments, system framenumber may be employed in physical layer for random access process inthe uplink and channel state transmission opportunities in uplinkcontrol channel. The transmission of a random access preamble, iftriggered by the MAC layer, is restricted to certain time and frequencyresources. For a given physical random access channel configurationindex and preamble format, a wireless device may be configured totransmit a preamble on specific frames, for example odd frame numbersand/or even frame numbers. For preamble format 4 and in TDD framestructure, the frequency multiplexing in a given frame may be donedepending, at least in part, as a function of the system frame number ofthe frame. In periodic channel state information reporting using PUCCH,a wireless device may employ at least in part, the system frame number,to calculate the transmission opportunities in the uplink controlchannel. For example, in the case where both wideband channel stateand/or quality reporting and sub-band channel state and/or qualityreporting are configured, the reporting instances for channel stateand/or quality reporting and sub-band channel state and/or qualityreporting subframes may be calculated based, at least in part, on systemframe number. In an example embodiment, physical uplink shared channelhopping sequences may be configured a function of system frame number.For example, in a physical uplink shared channel hopping, the set ofphysical resource blocks to be used for transmission in a slot may begiven according to a set of radio configuration parameters and as afunction of the system frame number.

In current LTE standard release 8, 9, and 10, each LTE carrier shouldcomprise a physical control channel. The base station should transmit,on each LTE carrier and each frame, control blocks comprising systemframe number in physical control channel. This provision makes eachcarrier a backward compatible carrier, and enables stand-alone operationof each carrier. Transmission of control blocks in each LTE carrier ineach frame increases carrier overhead and reduces spectral efficiency.There is a need to improve spectral efficiency in LTE systems. Exampleembodiments of the invention implements mechanisms that allow a carrierto operate without transmission of control blocks. Non-prime carriersmay be configured to operate without a physical broadcast channel. Theexample embodiments may provide a solution for reducing broadcastoverhead in LTE air interface. Non-prime carriers may be configured notto be backward compatible. The example embodiments enable a wirelessdevice to connect to a base station employing a prime carrier. Thewireless devices may not be able to acquire, select and connect to abase station employing a non-prime carrier. The base station mayconfigure non-prime carriers employing RRC signaling transmitted on aprime carrier. The base station and wireless device may employ, at leastin part, the system frame number transmitted on at least one primecarrier to operate an LTE interface transmitting and receivingsignals/packets on at least one prime carrier and at least one non-primecarrier.

According to some of the various aspects of embodiments, a base stationmay be configured to communicate employing a plurality of downlinkcarriers and a plurality of uplink carriers. The base station maybroadcast a control block in a plurality of control blocks. The controlblock may be broadcasted on a physical broadcast channel in a frame in aplurality of frames on a first downlink carrier (prime downlink carrier)in the plurality of downlink carriers. The control block may indicate anumber of symbols employed for transmission of a physical hybrid ARQchannel starting from the first OFDM symbol in a subframe in a firstplurality of subframes of the frame on the first downlink carrier. Thesecond downlink carrier (non-prime downlink carrier) may be configuredto operate without a physical hybrid ARQ channel employing the number ofOFDM symbols (indicated in the control block on the prime carrier)starting from the first OFDM symbol of the first plurality of subframes.The second downlink carrier may be configured with a different hybridARQ channel configuration or may be configured to operate without ahybrid ARQ on the second downlink carrier.

The base station may transmit a first plurality of downlink data packetson a first downlink data channel of the first downlink carrier. Theradio resources employed for the first downlink data channel in thesubframes may start from an OFDM symbol after the number of OFDM symbolsemployed for the physical hybrid ARQ channel. The radio resourcesemployed for the first downlink data channel in the subframes may startfrom an OFDM symbol subsequent to the OFDM symbols employed for aphysical downlink shared channel on the first downlink carrier. In afirst example configuration according to a control block transmitted inthe frame, the physical hybrid ARQ channel in subframes of the frame maybe transmitted on the first symbol of the subframes of a frame. In asecond example configuration according to a control block transmitted inthe frame, the physical hybrid ARQ channel in subframes of the frame maybe transmitted on the first, second and third symbol of the subframes ofa frame.

The base station may transmit at least one control message on the firstdownlink data channel to a wireless device. The at least one controlmessage may be configured to cause configuration of radio resources of asecond downlink data channel. In an example implementation, the at leastone control message may be configured to cause configuration of radioresources of a second downlink data channel to start from the first OFDMsymbol of subframes of a second downlink carrier in the plurality ofdownlink carriers.

The base station may receive a first plurality of uplink data packets ona first uplink data channel of a first uplink carrier corresponding tothe downlink carrier. The first uplink carrier may comprise: a) a firstportion of bandwidth employed for the first uplink data channel; and b)a second portion of the bandwidth employed for a first uplink controlchannel. In an example implementation option, a third portion of thebandwidth of the first uplink carrier may be employed for an uplinkphysical random access channel. The base station may receive a secondplurality of uplink data packets on a second uplink data channel of asecond uplink carrier corresponding to the second downlink carrier. Theentire active bandwidth of the second uplink carrier may be employed forthe second uplink data channel. If second uplink carrier includes randomaccess channel, the second uplink data channel radio resources mayexclude radio resources assigned to random access channel on the seconduplink carrier. The base station may transmit positive/negativeacknowledgements. The positive/negative acknowledgements may providepositive/negative acknowledgements for the first plurality of uplinkdata packets and the second plurality of uplink data packets. The basestation may receive channel state information for the first downlinkcarrier and the second downlink carrier on the first uplink controlchannel. Base station may receive on the first uplink control channel,positive/negative acknowledgements for at least one of a plurality ofdata packets transmitted on the first downlink data channel and thesecond downlink data channel. The second uplink carrier may beconfigured to operate without a physical uplink control channel.

According to some of the various aspects of embodiments, a wirelessdevice may be configured to communicate employing a plurality ofdownlink carriers and a plurality of uplink carriers. The wirelessdevice may receive a control block in a plurality of control blocks. Thecontrol block may be received on a physical broadcast channel in a framein a plurality of frames on a first downlink carrier (prime downlinkcarrier) in the plurality of downlink carriers. The control block mayindicate a number of symbols employed for reception of a physical hybridARQ channel starting from the first OFDM symbol in a subframe in a firstplurality of subframes of the frame on the first downlink carrier. Thesecond downlink carrier (non-prime downlink carrier) may be configuredto operate without a physical hybrid ARQ channel employing the number ofOFDM symbols (indicated in the control block on the prime carrier)starting from the first OFDM symbol of the first plurality of subframes.The second downlink carrier may be configured with a different hybridARQ channel configuration (for example, employing resource elements inresource blocks employed by an enhanced physical downlink controlchannel) or may be configured to operate without a hybrid ARQ on thesecond downlink carrier.

The wireless device may receive a first plurality of downlink datapackets on a first downlink data channel of the first downlink carrier.The radio resources employed for the first downlink data channel in thesubframes may start from an OFDM symbol after the number of OFDM symbolsemployed for the physical hybrid ARQ channel. The radio resourcesemployed for the first downlink data channel in the subframes may startfrom an OFDM symbol subsequent to the OFDM symbols employed for aphysical downlink shared channel on the first downlink carrier. In afirst example configuration according to a control block received in theframe, the physical hybrid ARQ channel in subframes of the frame may bereceived on the first symbol of the subframes of a frame. In a secondexample configuration according to a control block received in theframe, the physical hybrid ARQ channel in subframes of the frame may bereceived on the first, second and third symbol of the subframes of aframe.

The wireless device may receive at least one control message on thefirst downlink data channel to a wireless device. The at least onecontrol message may be configured to cause configuration of radioresources of a second downlink data channel. In an exampleimplementation, the at least one control message may be configured tocause configuration of radio resources of a second downlink data channelto start from the first OFDM symbol of subframes of a second downlinkcarrier in the plurality of downlink carriers.

The wireless device may transmit a first plurality of uplink datapackets on a first uplink data channel of a first uplink carriercorresponding to the downlink carrier. The first uplink carrier maycomprise: a) a first portion of bandwidth employed for the first uplinkdata channel; and b) a second portion of the bandwidth employed for afirst uplink control channel. In an example implementation option, athird portion of the bandwidth of the first uplink carrier may beemployed for an uplink physical random access channel. The wirelessdevice may transmit a second plurality of uplink data packets on asecond uplink data channel of a second uplink carrier corresponding tothe second downlink carrier. The entire active bandwidth of the seconduplink carrier may be employed for the second uplink data channel. Ifsecond uplink carrier includes random access channel, the second uplinkdata channel radio resources may exclude radio resources assigned torandom access channel on the second uplink carrier. The wireless devicemay receive positive/negative acknowledgements. The positive/negativeacknowledgements may provide positive/negative acknowledgements for thefirst plurality of uplink data packets and the second plurality ofuplink data packets. The wireless device may transmit channel stateinformation for the first downlink carrier and the second downlinkcarrier on the first uplink control channel. Wireless device maytransmit on the first uplink control channel, positive/negativeacknowledgements for at least one of a plurality of data packetsreceived on the first downlink data channel and the second downlink datachannel. The second uplink carrier may be configured to operate withouta physical uplink control channel.

According to some of the various aspects of embodiments, in a firstcarrier configuration, the at least one control message may establishthat no resource is allocated to physical hybrid ARQ channel on thesecond downlink carrier. The second downlink carrier may be configuredto operate without a physical hybrid ARQ channel. The base station maytransmit the physical hybrid ARQ channel on the first downlink carrier.The physical hybrid ARQ channel may provide positive or negativeacknowledgements for the first plurality of uplink data packets receivedon the first uplink carrier and the second plurality of uplink datapackets received on the second uplink carrier.

According to some of the various aspects of embodiments, in a secondcarrier configuration, the at least one control message may beconfigured to cause configuration of radio resources of a seconddownlink data channel to start from an offset OFDM symbol in a subset orall of the subframes of a second downlink carrier. For example, thesecond downlink data channel may start from the third symbol of a subsetor all of the subframes. The offset, for example, may be one, two, threeor four symbols.

According to some of the various aspects of embodiments, in a thirdexample carrier configuration, the at least one control message may beconfigured to cause configuration of radio resources of the seconduplink carrier. A first portion of the bandwidth of the second uplinkcarrier may be employed for the second uplink data channel. A secondportion of the bandwidth of the second uplink carrier is employed for asecond uplink control channel. The second uplink carrier may beconfigured to operate without a physical random access channel.

According to some of the various aspects of embodiments, a base stationmay be configured to communicate employing a plurality of downlinkcarriers and a plurality of uplink carriers. The base station maybroadcast a control block on a plurality of subcarriers substantially inthe center of the frequency band of a first downlink carrier (primedownlink carrier). The control block may be transmitted on the firstsubframe of a frame of a plurality of frames. The control block mayindicate the bandwidth of the first downlink carrier in terms of thenumber of downlink resource blocks. The control block may provideconfiguration parameters of a physical hybrid ARQ channel transmitted onthe first downlink carrier. The physical hybrid ARQ channel carryingpositive/negative acknowledgements for a first plurality of uplinkpackets received on an uplink channel of a first uplink carrier. Thefirst uplink carrier may correspond to the first downlink carrier. Thecontrol block may provide a system frame number for the frame.

The base station may transmit at least one control message on a firstdownlink data channel to a wireless device. The control message may beconfigured to cause configuration of: a) radio link parameters for thewireless device receiving the first downlink carrier (prime downlinkcarrier) and a second downlink carrier (non-prime downlink carrier); b)bandwidth of the second downlink carrier; and c) a second data channelon the second downlink carrier. The base station may transmit, employinga communication interface, a second plurality of data packets on thesecond data channel. The communication interface may employ, at least inpart, the system frame number in the frame of the first carrier. Thesecond downlink carrier may be configured to operate without a physicalbroadcast channel broadcasted in the second carrier. No physicalbroadcast channel may be transmitted on the second carrier.

The base station may transmit a second plurality of data packets on asecond data channel of the second downlink carrier. The base station mayreceive a third plurality of data packets on an uplink channel on asecond uplink carrier corresponding to the second downlink carrier. Thebase station may transmit positive/negative acknowledgements for thethird plurality of uplink packets employing the physical hybrid ARQchannel transmitted on the first downlink carrier. The second downlinkcarrier may be configured to operate without transmitting a HARQchannel.

The physical broadcast channel may be transmitted using a plurality ofsubcarriers substantially in the center of the frequency band of thefirst downlink carrier on the first subframe of a frame in the pluralityof frames. The downlink bandwidth of the first carrier may be indicatedin terms of number of downlink resource blocks. The physical hybrid ARQchannel may comprise positive/negative acknowledgements for a firstplurality of uplink packets received on an uplink channel on a firstuplink carrier. The base station may receive a second plurality of datapackets on an uplink channel on a second uplink carrier. The basestation may transmit positive/negative acknowledgements for the secondplurality of uplink packets employing the physical hybrid ARQ channeltransmitted on the first downlink carrier. The at least one controlmessage may comprise frequency band of the second downlink carrier.

According to some of the various aspects of embodiments, a wirelessdevice may be configured to communicate employing a plurality ofdownlink carriers and a plurality of uplink carriers. The wirelessdevice may receive a control block on a plurality of subcarrierssubstantially in the center of the frequency band of a first downlinkcarrier (prime downlink carrier). The control block may be received onthe first subframe of a frame of a plurality of frames. The controlblock may indicate the bandwidth of the first downlink carrier in termsof the number of downlink resource blocks. The control block may provideconfiguration parameters of a physical hybrid ARQ channel received onthe first downlink carrier. The physical hybrid ARQ channel carryingpositive/negative acknowledgements for a first plurality of uplinkpackets transmitted on an uplink channel of a first uplink carrier. Thefirst uplink carrier may correspond to the first downlink carrier. Thecontrol block may provide a system frame number for the frame.

The wireless device may receive from the base station at least onecontrol message on a first downlink data channel from a base station.The control message may be configured to cause configuration of: a)radio link parameters for the wireless device receiving the firstdownlink carrier (prime downlink carrier) and a second downlink carrier(non-prime downlink carrier); b) bandwidth of the second downlinkcarrier; and c) a second data channel on the second downlink carrier.The wireless device may receive, employing a communication interface, asecond plurality of data packets on the second data channel. Thecommunication interface may employ, at least in part, the system framenumber in the frame of the first carrier. The second downlink carriermay be configured to operate without a physical broadcast channelreceived in the second carrier. No physical broadcast channel may bereceived on the second carrier.

The wireless device may receive a second plurality of data packets on asecond data channel of the second downlink carrier. The wireless devicemay transmit a third plurality of data packets on an uplink channel on asecond uplink carrier corresponding to the second downlink carrier. Thewireless device may receive positive/negative acknowledgements for thethird plurality of uplink packets employing the physical hybrid ARQchannel received on the first downlink carrier. The second downlinkcarrier may be configured to operate without receiving a HARQ channel.

The physical broadcast channel may be received employing a plurality ofsubcarriers substantially in the center of the frequency band of thefirst downlink carrier on the first subframe of a frame in the pluralityof frames. The downlink bandwidth of the first carrier may be indicatedin terms of number of downlink resource blocks. The physical hybrid ARQchannel may comprise positive/negative acknowledgements for a firstplurality of uplink packets transmitted on an uplink channel on a firstuplink carrier. The wireless device may transmit a second plurality ofdata packets on an uplink channel on a second uplink carrier. Thewireless device may receive positive/negative acknowledgements for thesecond plurality of uplink packets employing the physical hybrid ARQchannel received on the first downlink carrier. The at least one controlmessage may comprise frequency band of the second downlink carrier.

In current LTE standard release 8, 9, and 10, each LTE carrier shouldcomprise a physical control channel. The base station should transmit,on each LTE carrier and each frame, control blocks comprising systemframe number, HARQ configuration, and carrier bandwidth in the physicalbroad cast control channel. Each LTE carrier should comprise a physicalhybrid ARQ channel. Hybrid ARQ channel employs the first symbol or thefirst three symbols of subframes of a frame depending on HARQconfiguration indicated in the control block transmitted in the physicalbroad cast control channel. This provision makes each carrier a backwardcompatible carrier, and enables stand-alone operation of each carrier.Transmission of control blocks in each LTE carrier in each frame, andreserving radio resources for hybrid physical ARQ channel in eachsubframe increases carrier overhead and reduces spectral efficiency.There is a need to improve spectral efficiency in LTE systems. Exampleembodiments of the invention implements mechanisms that allow a carrierto operate without transmission of control blocks and without allocatingresources to physical hybrid ARQ channel. Non-prime carriers may beconfigured to operate without a physical broadcast channel and physicalhybrid ARQ channel. The example embodiments may provide a solution forreducing overhead in LTE air interface. Non-prime carriers may beconfigured not to be backward compatible. The example embodiments enablea wireless device to connect to a base station employing a primecarrier. The wireless devices may not be able to acquire, select andconnect to a base station employing a non-prime carrier. The basestation may configure non-prime carriers employing RRC signalingtransmitted on a prime carrier.

According to some of the various aspects of embodiments, the packets inthe downlink may be transmitted via downlink physical channels. Thecarrying packets in the uplink may be transmitted via uplink physicalchannels. The baseband data representing a downlink physical channel maybe defined in terms of at least one of the following actions: scramblingof coded bits in codewords to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on layer(s) for transmission on the antenna port(s); mapping ofcomplex-valued modulation symbols for antenna port(s) to resourceelements; and/or generation of complex-valued time-domain OFDM signal(s)for antenna port(s).

Codeword, transmitted on the physical channel in one subframe, may bescrambled prior to modulation, resulting in a block of scrambled bits.The scrambling sequence generator may be initialized at the start ofsubframe(s). Codeword(s) may be modulated using QPSK, 16QAM, 64QAM,128QAM, and/or the like resulting in a block of complex-valuedmodulation symbols. The complex-valued modulation symbols for codewordsto be transmitted may be mapped onto one or several layers. Fortransmission on a single antenna port, a single layer may be used. Forspatial multiplexing, the number of layers may be less than or equal tothe number of antenna port(s) used for transmission of the physicalchannel. The case of a single codeword mapped to multiple layers may beapplicable when the number of cell-specific reference signals is four orwhen the number of UE-specific reference signals is two or larger. Fortransmit diversity, there may be one codeword and the number of layersmay be equal to the number of antenna port(s) used for transmission ofthe physical channel.

Common reference signal(s) may be transmitted in physical antennaport(s). Common reference signal(s) may be cell-specific referencesignal(s) (RS) used for demodulation and/or measurement purposes.Channel estimation accuracy using common reference signal(s) may bereasonable for demodulation (high RS density). Common referencesignal(s) may be defined for LTE technologies, LTE-advancedtechnologies, and/or the like. Demodulation reference signal(s) may betransmitted in virtual antenna port(s) (i.e., layer or stream). Channelestimation accuracy using demodulation reference signal(s) may bereasonable within allocated time/frequency resources. Demodulationreference signal(s) may be defined for LTE-advanced technology and maynot be applicable to LTE technology. Measurement reference signal(s),may also called CSI (channel state information) reference signal(s), maybe transmitted in physical antenna port(s) or virtualized antennaport(s). Measurement reference signal(s) may be Cell-specific RS usedfor measurement purposes. Channel estimation accuracy may be relativelylower than demodulation RS. CSI reference signal(s) may be defined forLTE-advanced technology and may not be applicable to LTE technology.

In at least one of the various embodiments, uplink physical channel(s)may correspond to a set of resource elements carrying informationoriginating from higher layers. The following example uplink physicalchannel(s) may be defined for uplink: a) Physical Uplink Shared Channel(PUSCH), b) Physical Uplink Control Channel (PUCCH), c) Physical RandomAccess Channel (PRACH), and/or the like. Uplink physical signal(s) maybe used by the physical layer and may not carry information originatingfrom higher layers. For example, reference signal(s) may be consideredas uplink physical signal(s). Transmitted signal(s) in slot(s) may bedescribed by one or several resource grids including, for example,subcarriers and SC-FDMA or OFDMA symbols. Antenna port(s) may be definedsuch that the channel over which symbol(s) on antenna port(s) may beconveyed and/or inferred from the channel over which other symbol(s) onthe same antenna port(s) is/are conveyed. There may be one resource gridper antenna port. The antenna port(s) used for transmission of physicalchannel(s) or signal(s) may depend on the number of antenna port(s)configured for the physical channel(s) or signal(s).

Element(s) in a resource grid may be called a resource element. Aphysical resource block may be defined as N consecutive SC-FDMA symbolsin the time domain and/or M consecutive subcarriers in the frequencydomain, wherein M and N may be pre-defined integer values. Physicalresource block(s) in uplink(s) may comprise of M×N resource elements.For example, a physical resource block may correspond to one slot in thetime domain and 180 kHz in the frequency domain. Baseband signal(s)representing the physical uplink shared channel may be defined in termsof: a) scrambling, b) modulation of scrambled bits to generatecomplex-valued symbols, c) mapping of complex-valued modulation symbolsonto one or several transmission layers, d) transform precoding togenerate complex-valued symbols, e) precoding of complex-valued symbols,f) mapping of precoded complex-valued symbols to resource elements, g)generation of complex-valued time-domain SC-FDMA signal(s) for antennaport(s), and/or the like.

For codeword(s), block(s) of bits may be scrambled with UE-specificscrambling sequence(s) prior to modulation, resulting in block(s) ofscrambled bits. Complex-valued modulation symbols for codeword(s) to betransmitted may be mapped onto one, two, or more layers. For spatialmultiplexing, layer mapping(s) may be performed according to pre-definedformula (s). The number of layers may be less than or equal to thenumber of antenna port(s) used for transmission of physical uplinkshared channel(s). The example of a single codeword mapped to multiplelayers may be applicable when the number of antenna port(s) used forPUSCH is, for example, four. For layer(s), the block of complex-valuedsymbols may be divided into multiple sets, each corresponding to oneSC-FDMA symbol. Transform precoding may be applied. For antenna port(s)used for transmission of the PUSCH in a subframe, block(s) ofcomplex-valued symbols may be multiplied with an amplitude scalingfactor in order to conform to a required transmit power, and mapped insequence to physical resource block(s) on antenna port(s) and assignedfor transmission of PUSCH.

According to some of the various embodiments, data may arrive to thecoding unit in the form of two transport blocks every transmission timeinterval (TTI) per UL cell. The following coding actions may beidentified for transport block(s) of an uplink carrier: a) Add CRC tothe transport block, b) Code block segmentation and code block CRCattachment, c) Channel coding of data and control information, d) Ratematching, e) Code block concatenation. f) Multiplexing of data andcontrol information, g) Channel interleaver, h) Error detection may beprovided on UL-SCH (uplink shared channel) transport block(s) through aCyclic Redundancy Check (CRC), and/or the like. Transport block(s) maybe used to calculate CRC parity bits. Code block(s) may be delivered tochannel coding block(s). Code block(s) may be individually turboencoded. Turbo coded block(s) may be delivered to rate matchingblock(s).

Physical uplink control channel(s) (PUCCH) may carry uplink controlinformation. Simultaneous transmission of PUCCH and PUSCH from the sameUE may be supported if enabled by higher layers. For a type 2 framestructure, the PUCCH may not be transmitted in the UpPTS field. PUCCHmay use one resource block in each of the two slots in a subframe.Resources allocated to UE and PUCCH configuration(s) may be transmittedvia control messages. PUCCH may comprise: a) positive and negativeacknowledgements for data packets transmitted at least one downlinkcarrier, b) channel state information for at least one downlink carrier,c) scheduling request, and/or the like.

According to some of the various aspects of embodiments, cell search maybe the procedure by which a wireless device may acquire time andfrequency synchronization with a cell and may detect the physical layerCell ID of that cell (transmitter). An example embodiment forsynchronization signal and cell search is presented below. A cell searchmay support a scalable overall transmission bandwidth corresponding to 6resource blocks and upwards. Primary and secondary synchronizationsignals may be transmitted in the downlink and may facilitate cellsearch. For example, 504 unique physical-layer cell identities may bedefined using synchronization signals. The physical-layer cellidentities may be grouped into 168 unique physical-layer cell-identitygroups, group(s) containing three unique identities. The grouping may besuch that physical-layer cell identit(ies) is part of a physical-layercell-identity group. A physical-layer cell identity may be defined by anumber in the range of 0 to 167, representing the physical-layercell-identity group, and a number in the range of 0 to 2, representingthe physical-layer identity within the physical-layer cell-identitygroup. The synchronization signal may include a primary synchronizationsignal and a secondary synchronization signal.

According to some of the various aspects of embodiments, the sequenceused for a primary synchronization signal may be generated from afrequency-domain Zadoff-Chu sequence according to a pre-defined formula.A Zadoff-Chu root sequence index may also be predefined in aspecification. The mapping of the sequence to resource elements maydepend on a frame structure. The wireless device may not assume that theprimary synchronization signal is transmitted on the same antenna portas any of the downlink reference signals. The wireless device may notassume that any transmission instance of the primary synchronizationsignal is transmitted on the same antenna port, or ports, used for anyother transmission instance of the primary synchronization signal. Thesequence may be mapped to the resource elements according to apredefined formula.

For FDD frame structure, a primary synchronization signal may be mappedto the last OFDM symbol in slots 0 and 10. For TDD frame structure, theprimary synchronization signal may be mapped to the third OFDM symbol insubframes 1 and 6. Some of the resource elements allocated to primary orsecondary synchronization signals may be reserved and not used fortransmission of the primary synchronization signal.

According to some of the various aspects of embodiments, the sequenceused for a secondary synchronization signal may be an interleavedconcatenation of two length-31 binary sequences. The concatenatedsequence may be scrambled with a scrambling sequence given by a primarysynchronization signal. The combination of two length-31 sequencesdefining the secondary synchronization signal may differ betweensubframe 0 and subframe 5 according to predefined formula (s). Themapping of the sequence to resource elements may depend on the framestructure. In a subframe for FDD frame structure and in a half-frame forTDD frame structure, the same antenna port as for the primarysynchronization signal may be used for the secondary synchronizationsignal. The sequence may be mapped to resource elements according to apredefined formula.

Example embodiments for the physical channels configuration will now bepresented. Other examples may also be possible. A physical broadcastchannel may be scrambled with a cell-specific sequence prior tomodulation, resulting in a block of scrambled bits. PBCH may bemodulated using QPSK, and/or the like. The block of complex-valuedsymbols for antenna port(s) may be transmitted during consecutive radioframes, for example, four consecutive radio frames. In some embodimentsthe PBCH data may arrive to the coding unit in the form of a onetransport block every transmission time interval (TTI) of 40 ms. Thefollowing coding actions may be identified. Add CRC to the transportblock, channel coding, and rate matching. Error detection may beprovided on PBCH transport blocks through a Cyclic Redundancy Check(CRC). The transport block may be used to calculate the CRC parity bits.The parity bits may be computed and attached to the BCH (broadcastchannel) transport block. After the attachment, the CRC bits may bescrambled according to the transmitter transmit antenna configuration.Information bits may be delivered to the channel coding block and theymay be tail biting convolutionally encoded. A tail bitingconvolutionally coded block may be delivered to the rate matching block.The coded block may be rate matched before transmission.

A master information block may be transmitted in PBCH and may includesystem information transmitted on broadcast channel(s). The masterinformation block may include downlink bandwidth, system framenumber(s), and PHICH (physical hybrid-ARQ indicator channel)configuration. Downlink bandwidth may be the transmission bandwidthconfiguration, in terms of resource blocks in a downlink, for example 6may correspond to 6 resource blocks, 15 may correspond to 15 resourceblocks and so on. System frame number(s) may define the N (for exampleN=8) most significant bits of the system frame number. The M (forexample M=2) least significant bits of the SFN may be acquiredimplicitly in the PBCH decoding. For example, timing of a 40 ms PBCH TTImay indicate 2 least significant bits (within 40 ms PBCH TTI, the firstradio frame: 00, the second radio frame: 01, the third radio frame: 10,the last radio frame: 11). One value may apply for other carriers in thesame sector of a base station (the associated functionality is common(e.g. not performed independently for each cell). PHICH configuration(s)may include PHICH duration, which may be normal (e.g. one symbolduration) or extended (e.g. 3 symbol duration).

Physical control format indicator channel(s) (PCFICH) may carryinformation about the number of OFDM symbols used for transmission ofPDCCHs (physical downlink control channel) in a subframe. The set ofOFDM symbols possible to use for PDCCH in a subframe may depend on manyparameters including, for example, downlink carrier bandwidth, in termsof downlink resource blocks. PCFICH transmitted in one subframe may bescrambled with cell-specific sequence(s) prior to modulation, resultingin a block of scrambled bits. A scrambling sequence generator(s) may beinitialized at the start of subframe(s). Block (s) of scrambled bits maybe modulated using QPSK. Block(s) of modulation symbols may be mapped toat least one layer and precoded resulting in a block of vectorsrepresenting the signal for at least one antenna port. Instances ofPCFICH control channel(s) may indicate one of several (e.g. 3) possiblevalues after being decoded. The range of possible values of instance(s)of the first control channel may depend on the first carrier bandwidth.

According to some of the various embodiments, physical downlink controlchannel(s) may carry scheduling assignments and other controlinformation. The number of resource-elements not assigned to PCFICH orPHICH may be assigned to PDCCH. PDCCH may support multiple formats.Multiple PDCCH packets may be transmitted in a subframe. PDCCH may becoded by tail biting convolutionally encoder before transmission. PDCCHbits may be scrambled with a cell-specific sequence prior to modulation,resulting in block(s) of scrambled bits. Scrambling sequencegenerator(s) may be initialized at the start of subframe(s). Block(s) ofscrambled bits may be modulated using QPSK. Block(s) of modulationsymbols may be mapped to at least one layer and precoded resulting in ablock of vectors representing the signal for at least one antenna port.PDCCH may be transmitted on the same set of antenna ports as the PBCH,wherein PBCH is a physical broadcast channel broadcasting at least onebasic system information field.

According to some of the various embodiments, scheduling controlpacket(s) may be transmitted for packet(s) or group(s) of packetstransmitted in downlink shared channel(s). Scheduling control packet(s)may include information about subcarriers used for packettransmission(s). PDCCH may also provide power control commands foruplink channels. OFDM subcarriers that are allocated for transmission ofPDCCH may occupy the bandwidth of downlink carrier(s). PDCCH channel(s)may carry a plurality of downlink control packets in subframe(s). PDCCHmay be transmitted on downlink carrier(s) starting from the first OFDMsymbol of subframe(s), and may occupy up to multiple symbol duration(s)(e.g. 3 or 4).

According to some of the various embodiments, PHICH may carry thehybrid-ARQ (automatic repeat request) ACK/NACK. Multiple PHICHs mappedto the same set of resource elements may constitute a PHICH group, wherePHICHs within the same PHICH group may be separated through differentorthogonal sequences. PHICH resource(s) may be identified by the indexpair (group, sequence), where group(s) may be the PHICH group number(s)and sequence(s) may be the orthogonal sequence index within thegroup(s). For frame structure type 1, the number of PHICH groups maydepend on parameters from higher layers (RRC). For frame structure type2, the number of PHICH groups may vary between downlink subframesaccording to a pre-defined arrangement. Block(s) of bits transmitted onone PHICH in one subframe may be modulated using BPSK or QPSK, resultingin a block(s) of complex-valued modulation symbols. Block(s) ofmodulation symbols may be symbol-wise multiplied with an orthogonalsequence and scrambled, resulting in a sequence of modulation symbols

Other arrangements for PCFICH, PHICH, PDCCH, and/or PDSCH may besupported. The configurations presented here are for example purposes.In another example, resources PCFICH, PHICH, and/or PDCCH radioresources may be transmitted in radio resources including a subset ofsubcarriers and pre-defined time duration in each or some of thesubframes. In an example, PUSCH resource(s) may start from the firstsymbol. In another example embodiment, radio resource configuration(s)for PUSCH, PUCCH, and/or PRACH (physical random access channel) may usea different configuration. For example, channels may be timemultiplexed, or time/frequency multiplexed when mapped to uplink radioresources.

According to some of the various aspects of embodiments, the physicallayer random access preamble may comprise a cyclic prefix of length Tcpand a sequence part of length Tseq. The parameter values may bepre-defined and depend on the frame structure and a random accessconfiguration. In an example embodiment, Tcp may be 0.1 msec, and Tseqmay be 0.9 msec. Higher layers may control the preamble format. Thetransmission of a random access preamble, if triggered by the MAC layer,may be restricted to certain time and frequency resources. The start ofa random access preamble may be aligned with the start of thecorresponding uplink subframe at a wireless device.

According to an example embodiment, random access preambles may begenerated from Zadoff-Chu sequences with a zero correlation zone,generated from one or several root Zadoff-Chu sequences. In anotherexample embodiment, the preambles may also be generated using otherrandom sequences such as Gold sequences. The network may configure theset of preamble sequences a wireless device may be allowed to use.According to some of the various aspects of embodiments, there may be amultitude of preambles (e.g. 64) available in cell(s). From the physicallayer perspective, the physical layer random access procedure mayinclude the transmission of random access preamble(s) and random accessresponse(s). Remaining message(s) may be scheduled for transmission by ahigher layer on the shared data channel and may not be considered partof the physical layer random access procedure. For example, a randomaccess channel may occupy 6 resource blocks in a subframe or set ofconsecutive subframes reserved for random access preamble transmissions.

According to some of the various embodiments, the following actions maybe followed for a physical random access procedure: 1) layer 1 proceduremay be triggered upon request of a preamble transmission by higherlayers; 2) a preamble index, a target preamble received power, acorresponding RA-RNTI (random access-radio network temporary identifier)and/or a PRACH resource may be indicated by higher layers as part of arequest; 3) a preamble transmission power P_PRACH may be determined; 4)a preamble sequence may be selected from the preamble sequence set usingthe preamble index; 5) a single preamble may be transmitted usingselected preamble sequence(s) with transmission power P_PRACH on theindicated PRACH resource; 6) detection of a PDCCH with the indicated RARmay be attempted during a window controlled by higher layers; and/or thelike. If detected, the corresponding downlink shared channel transportblock may be passed to higher layers. The higher layers may parsetransport block(s) and/or indicate an uplink grant to the physicallayer(s).

According to some of the various aspects of embodiments, a random accessprocedure may be initiated by a physical downlink control channel(PDCCH) order and/or by the MAC sublayer in a wireless device. If awireless device receives a PDCCH transmission consistent with a PDCCHorder masked with its radio identifier, the wireless device may initiatea random access procedure. Preamble transmission(s) on physical randomaccess channel(s) (PRACH) may be supported on a first uplink carrier andreception of a PDCCH order may be supported on a first downlink carrier.

Before a wireless device initiates transmission of a random accesspreamble, it may access one or many of the following types ofinformation: a) available set(s) of PRACH resources for the transmissionof a random access preamble; b) group(s) of random access preambles andset(s) of available random access preambles in group(s); c) randomaccess response window size(s); d) power-ramping factor(s); e) maximumnumber(s) of preamble transmission(s); f) initial preamble power; g)preamble format based offset(s); h) contention resolution timer(s);and/or the like. These parameters may be updated from upper layers ormay be received from the base station before random access procedure(s)may be initiated.

According to some of the various aspects of embodiments, a wirelessdevice may select a random access preamble using available information.The preamble may be signaled by a base station or the preamble may berandomly selected by the wireless device. The wireless device maydetermine the next available subframe containing PRACH permitted byrestrictions given by the base station and the physical layer timingrequirements for TDD or FDD. Subframe timing and the timing oftransmitting the random access preamble may be determined based, atleast in part, on synchronization signals received from the base stationand/or the information received from the base station. The wirelessdevice may proceed to the transmission of the random access preamblewhen it has determined the timing. The random access preamble may betransmitted on a second plurality of subcarriers on the first uplinkcarrier.

According to some of the various aspects of embodiments, once a randomaccess preamble is transmitted, a wireless device may monitor the PDCCHof a first downlink carrier for random access response(s), in a randomaccess response window. There may be a pre-known identifier in PDCCHthat indentifies a random access response. The wireless device may stopmonitoring for random access response(s) after successful reception of arandom access response containing random access preamble identifiersthat matches the transmitted random access preamble and/or a randomaccess response address to a wireless device identifier. A base stationrandom access response may include a time alignment command. Thewireless device may process the received time alignment command and mayadjust its uplink transmission timing according the time alignment valuein the command. For example, in a random access response, a timealignment command may be coded using 11 bits, where an amount of thetime alignment may be based on the value in the command. In an exampleembodiment, when an uplink transmission is required, the base stationmay provide the wireless device a grant for uplink transmission.

If no random access response is received within the random accessresponse window, and/or if none of the received random access responsescontains a random access preamble identifier corresponding to thetransmitted random access preamble, the random access response receptionmay be considered unsuccessful and the wireless device may, based on thebackoff parameter in the wireless device, select a random backoff timeand delay the subsequent random access transmission by the backoff time,and may retransmit another random access preamble.

According to some of the various aspects of embodiments, a wirelessdevice may transmit packets on an uplink carrier. Uplink packettransmission timing may be calculated in the wireless device using thetiming of synchronization signal(s) received in a downlink. Uponreception of a timing alignment command by the wireless device, thewireless device may adjust its uplink transmission timing. The timingalignment command may indicate the change of the uplink timing relativeto the current uplink timing. The uplink transmission timing for anuplink carrier may be determined using time alignment commands and/ordownlink reference signals.

According to some of the various aspects of embodiments, a timealignment command may indicate timing adjustment for transmission ofsignals on uplink carriers. For example, a time alignment command mayuse 6 bits. Adjustment of the uplink timing by a positive or a negativeamount indicates advancing or delaying the uplink transmission timing bya given amount respectively.

For a timing alignment command received on subframe n, the correspondingadjustment of the timing may be applied with some delay, for example, itmay be applied from the beginning of subframe n+6. When the wirelessdevice's uplink transmissions in subframe n and subframe n+1 areoverlapped due to the timing adjustment, the wireless device maytransmit complete subframe n and may not transmit the overlapped part ofsubframe n+1.

According to some of the various aspects of embodiments, a wirelessdevice may include a configurable timer (timeAlignmentTimer) that may beused to control how long the wireless device is considered uplink timealigned. When a timing alignment command MAC control element isreceived, the wireless device may apply the timing alignment command andstart or restart timeAlignmentTimer. The wireless device may not performany uplink transmission except the random access preamble transmissionwhen timeAlignmentTimer is not running or when it exceeds its limit. Thetime alignment command may substantially align frame and subframereception timing of a first uplink carrier and at least one additionaluplink carrier. According to some of the various aspects of embodiments,the time alignment command value range employed during a random accessprocess may be substantially larger than the time alignment commandvalue range during active data transmission. In an example embodiment,uplink transmission timing may be maintained on a per time alignmentgroup (TAG) basis. Carrier(s) may be grouped in TAGs, and TAG(s) mayhave their own downlink timing reference, time alignment timer, and/ortime alignment commands. Group(s) may have their own random accessprocess. Time alignment commands may be directed to a time alignmentgroup. The TAG, including the primary cell may be called a primary TAG(pTAG) and the TAG not including the primary cell may be called asecondary TAG (sTAG).

According to some of the various aspects of embodiments, controlmessage(s) or control packet(s) may be scheduled for transmission in aphysical downlink shared channel (PDSCH) and/or physical uplink sharedchannel PUSCH. PDSCH and PUSCH may carry control and datamessage(s)/packet(s). Control message(s) and/or packet(s) may beprocessed before transmission. For example, the control message(s)and/or packet(s) may be fragmented or multiplexed before transmission. Acontrol message in an upper layer may be processed as a data packet inthe MAC or physical layer. For example, system information block(s) aswell as data traffic may be scheduled for transmission in PDSCH. Datapacket(s) may be encrypted packets.

According to some of the various aspects of embodiments, data packet(s)may be encrypted before transmission to secure packet(s) from unwantedreceiver(s). Desired recipient(s) may be able to decrypt the packet(s).A first plurality of data packet(s) and/or a second plurality of datapacket(s) may be encrypted using an encryption key and at least oneparameter that may change substantially rapidly over time. Theencryption mechanism may provide a transmission that may not be easilyeavesdropped by unwanted receivers. The encryption mechanism may includeadditional parameter(s) in an encryption module that changessubstantially rapidly in time to enhance the security mechanism. Examplevarying parameter(s) may comprise various types of system counter(s),such as system frame number. Substantially rapidly may for example implychanging on a per subframe, frame, or group of subframes basis.Encryption may be provided by a PDCP layer between the transmitter andreceiver, and/or may be provided by the application layer. Additionaloverhead added to packet(s) by lower layers such as RLC, MAC, and/orPhysical layer may not be encrypted before transmission. In thereceiver, the plurality of encrypted data packet(s) may be decryptedusing a first decryption key and at least one first parameter. Theplurality of data packet(s) may be decrypted using an additionalparameter that changes substantially rapidly over time.

According to some of the various aspects of embodiments, a wirelessdevice may be preconfigured with one or more carriers. When the wirelessdevice is configured with more than one carrier, the base station and/orwireless device may activate and/or deactivate the configured carriers.One of the carriers (the primary carrier) may always be activated. Othercarriers may be deactivated by default and/or may be activated by a basestation when needed. A base station may activate and deactivate carriersby sending an activation/deactivation MAC control element. Furthermore,the UE may maintain a carrier deactivation timer per configured carrierand deactivate the associated carrier upon its expiry. The same initialtimer value may apply to instance(s) of the carrier deactivation timer.The initial value of the timer may be configured by a network. Theconfigured carriers (unless the primary carrier) may be initiallydeactivated upon addition and after a handover.

According to some of the various aspects of embodiments, if a wirelessdevice receives an activation/deactivation MAC control elementactivating the carrier, the wireless device may activate the carrier,and/or may apply normal carrier operation including: sounding referencesignal transmissions on the carrier, CQI (channel qualityindicator)/PMI(precoding matrix indicator)/RI(ranking indicator)reporting for the carrier, PDCCH monitoring on the carrier, PDCCHmonitoring for the carrier, start or restart the carrier deactivationtimer associated with the carrier, and/or the like. If the devicereceives an activation/deactivation MAC control element deactivating thecarrier, and/or if the carrier deactivation timer associated with theactivated carrier expires, the base station or device may deactivate thecarrier, and may stop the carrier deactivation timer associated with thecarrier, and/or may flush HARQ buffers associated with the carrier.

If PDCCH on a carrier scheduling the activated carrier indicates anuplink grant or a downlink assignment for the activated carrier, thedevice may restart the carrier deactivation timer associated with thecarrier. When a carrier is deactivated, the wireless device may nottransmit SRS (sounding reference signal) for the carrier, may not reportCQI/PMI/RI for the carrier, may not transmit on UL-SCH for the carrier,may not monitor the PDCCH on the carrier, and/or may not monitor thePDCCH for the carrier.

A process to assign subcarriers to data packets may be executed by a MAClayer scheduler. The decision on assigning subcarriers to a packet maybe made based on data packet size, resources required for transmissionof data packets (number of radio resource blocks), modulation and codingassigned to data packet(s), QoS required by the data packets (i.e. QoSparameters assigned to data packet bearer), the service class of asubscriber receiving the data packet, or subscriber device capability, acombination of the above, and/or the like.

According to some of the various aspects of embodiments, packets may bereferred to service data units and/or protocols data units at Layer 1,Layer 2 and/or Layer 3 of the communications network. Layer 2 in an LTEnetwork may include three sub-layers: PDCP sub-layer, RLC sub-layer, andMAC sub-layer. A layer 2 packet may be a PDCP packet, an RLC packet or aMAC layer packet. Layer 3 in an LTE network may be Internet Protocol(IP) layer, and a layer 3 packet may be an IP data packet. Packets maybe transmitted and received via an air interface physical layer. Apacket at the physical layer may be called a transport block. Many ofthe various embodiments may be implemented at one or many differentcommunication network layers. For example, some of the actions may beexecuted by the PDCP layer and some others by the MAC layer.

According to some of the various aspects of embodiments, subcarriersand/or resource blocks may comprise a plurality of physical subcarriersand/or resource blocks. In another example embodiment, subcarriers maybe a plurality of virtual and/or logical subcarriers and/or resourceblocks.

According to some of the various aspects of embodiments, a radio bearermay be a GBR (guaranteed bit rate) bearer and/or a non-GBR bearer. A GBRand/or guaranteed bit rate bearer may be employed for transfer ofreal-time packets, and/or a non-GBR bearer may be used for transfer ofnon-real-time packets. The non-GBR bearer may be assigned a plurality ofattributes including: a scheduling priority, an allocation and retentionpriority, a portable device aggregate maximum bit rate, and/or the like.These parameters may be used by the scheduler in scheduling non-GBRpackets. GBR bearers may be assigned attributes such as delay, jitter,packet loss parameters, and/or the like.

According to some of the various aspects of embodiments, subcarriers mayinclude data subcarrier symbols and pilot subcarrier symbols. Pilotsymbols may not carry user data, and may be included in the transmissionto help the receiver to perform synchronization, channel estimationand/or signal quality detection. Base stations and wireless devices(wireless receiver) may use different methods to generate and transmitpilot symbols along with information symbols.

According to some of the various aspects of embodiments, the transmitterin the disclosed embodiments of the present invention may be a wirelessdevice (also called user equipment), a base station (also calledeNodeB), a relay node transmitter, and/or the like. The receiver in thedisclosed embodiments of the present invention may be a wireless device(also called user equipment-UE), a base station (also called eNodeB), arelay node receiver, and/or the like. According to some of the variousaspects of embodiments of the present invention, layer 1 (physicallayer) may be based on OFDMA or SC-FDMA. Time may be divided intoframe(s) with fixed duration. Frame(s) may be divided into substantiallyequally sized subframes, and subframe(s) may be divided intosubstantially equally sized slot(s). A plurality of OFDM or SC-FDMAsymbol(s) may be transmitted in slot(s). OFDMA or SC-FDMA symbol(s) maybe grouped into resource block(s). A scheduler may assign resource(s) inresource block unit(s), and/or a group of resource block unit(s).Physical resource block(s) may be resources in the physical layer, andlogical resource block(s) may be resource block(s) used by the MAClayer. Similar to virtual and physical subcarriers, resource block(s)may be mapped from logical to physical resource block(s). Logicalresource block(s) may be contiguous, but corresponding physical resourceblock(s) may be non-contiguous. Some of the various embodiments of thepresent invention may be implemented at the physical or logical resourceblock level(s).

According to some of the various aspects of embodiments, layer 2transmission may include PDCP (packet data convergence protocol), RLC(radio link control), MAC (media access control) sub-layers, and/or thelike. MAC may be responsible for the multiplexing and mapping of logicalchannels to transport channels and vice versa. A MAC layer may performchannel mapping, scheduling, random access channel procedures, uplinktiming maintenance, and/or the like.

According to some of the various aspects of embodiments, the MAC layermay map logical channel(s) carrying RLC PDUs (packet data unit) totransport channel(s). For transmission, multiple SDUs (service dataunit) from logical channel(s) may be mapped to the Transport Block (TB)to be sent over transport channel(s). For reception, TBs from transportchannel(s) may be demultiplexed and assigned to corresponding logicalchannel(s). The MAC layer may perform scheduling related function(s) inboth the uplink and downlink and thus may be responsible for transportformat selection associated with transport channel(s). This may includeHARQ functionality. Since scheduling may be done at the base station,the MAC layer may be responsible for reporting scheduling relatedinformation such as UE (user equipment or wireless device) bufferoccupancy and power headroom. It may also handle prioritization fromboth an inter-UE and intra-UE logical channel perspective. MAC may alsobe responsible for random access procedure(s) for the uplink that may beperformed following either a contention and non-contention basedprocess. UE may need to maintain timing synchronization with cell(s).The MAC layer may perform procedure(s) for periodic synchronization.

According to some of the various aspects of embodiments, the MAC layermay be responsible for the mapping of multiple logical channel(s) totransport channel(s) during transmission(s), and demultiplexing andmapping of transport channel data to logical channel(s) duringreception. A MAC PDU may include of a header that describes the formatof the PDU itself, which may include control element(s), SDUs, Padding,and/or the like. The header may be composed of multiple sub-headers, onefor constituent part(s) of the MAC PDU. The MAC may also operate in atransparent mode, where no header may be pre-pended to the PDU.Activation command(s) may be inserted into packet(s) using a MAC controlelement.

According to some of the various aspects of embodiments, the MAC layerin some wireless device(s) may report buffer size(s) of either a singleLogical Channel Group (LCG) or a group of LCGs to a base station. An LCGmay be a group of logical channels identified by an LCG ID. The mappingof logical channel(s) to LCG may be set up during radio configuration.Buffer status report(s) may be used by a MAC scheduler to assign radioresources for packet transmission from wireless device(s). HARQ and ARQprocesses may be used for packet retransmission to enhance thereliability of radio transmission and reduce the overall probability ofpacket loss.

According to some of the various aspects of embodiments, an RLCsub-layer may control the applicability and functionality of errorcorrection, concatenation, segmentation, re-segmentation, duplicatedetection, in-sequence delivery, and/or the like. Other functions of RLCmay include protocol error detection and recovery, and/or SDU discard.The RLC sub-layer may receive data from upper layer radio bearer(s)(signaling and data) called service data unit(s) (SDU). The transmissionentities in the RLC layer may convert RLC SDUs to RLC PDU afterperforming functions such as segmentation, concatenation, adding RLCheader(s), and/or the like. In the other direction, receiving entitiesmay receive RLC PDUs from the MAC layer. After performing reordering,the PDUs may be assembled back into RLC SDUs and delivered to the upperlayer. RLC interaction with a MAC layer may include: a) data transferfor uplink and downlink through logical channel(s); b) MAC notifies RLCwhen a transmission opportunity becomes available, including the size oftotal number of RLC PDUs that may be transmitted in the currenttransmission opportunity, and/or c) the MAC entity at the transmittermay inform RLC at the transmitter of HARQ transmission failure.

According to some of the various aspects of embodiments, PDCP (packetdata convergence protocol) may comprise a layer 2 sub-layer on top ofRLC sub-layer. The PDCP may be responsible for a multitude of functions.First, the PDCP layer may transfer user plane and control plane data toand from upper layer(s). PDCP layer may receive SDUs from upper layer(s)and may send PDUs to the lower layer(s). In other direction, PDCP layermay receive PDUs from the lower layer(s) and may send SDUs to upperlayer(s). Second, the PDCP may be responsible for security functions. Itmay apply ciphering (encryption) for user and control plane bearers, ifconfigured. It may also perform integrity protection for control planebearer(s), if configured. Third, the PDCP may perform header compressionservice(s) to improve the efficiency of over the air transmission. Theheader compression may be based on robust header compression (ROHC).ROHC may be performed on VOIP packets. Fourth, the PDCP may beresponsible for in-order delivery of packet(s) and duplicate detectionservice(s) to upper layer(s) after handover(s). After handover, thesource base station may transfer unacknowledged packet(s)s to targetbase station when operating in RLC acknowledged mode (AM). The targetbase station may forward packet(s)s received from the source basestation to the UE (user equipment).

In this specification, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” In this specification,the term “may” is to be interpreted as “may, for example,” In otherwords, the term “may” is indicative that the phrase following the term“may” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e hardware with a biological element) or acombination thereof, all of which are behaviorally equivalent. Forexample, modules may be implemented as a software routine written in acomputer language configured to be executed by a hardware machine (suchas C, C++, Fortran, Java, Basic, Matlab or the like) or amodeling/simulation program such as Simulink, Stateflow, GNU Octave, orLabVIEWMathScript. Additionally, it may be possible to implement modulesusing physical hardware that incorporates discrete or programmableanalog, digital and/or quantum hardware. Examples of programmablehardware comprise: computers, microcontrollers, microprocessors,application-specific integrated circuits (ASICs); field programmablegate arrays (FPGAs); and complex programmable logic devices (CPLDs).Computers, microcontrollers and microprocessors are programmed usinglanguages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDsare often programmed using hardware description languages (HDL) such asVHSIC hardware description language (VHDL) or Verilog that configureconnections between internal hardware modules with lesser functionalityon a programmable device. Finally, it needs to be emphasized that theabove mentioned technologies are often used in combination to achievethe result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using FDD communication systems. However, one skilled in the art willrecognize that embodiments of the invention may also be implemented inTDD communication systems. The disclosed methods and systems may beimplemented in wireless or wireline systems. The features of variousembodiments presented in this invention may be combined. One or manyfeatures (method or system) of one embodiment may be implemented inother embodiments. Only a limited number of example combinations areshown to indicate to one skilled in the art the possibility of featuresthat may be combined in various embodiments to create enhancedtransmission and reception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112, paragraph 6. Claims that do not expressly include the phrase“means for” or “step for” are not to be interpreted under 35 U.S.C. 112,paragraph 6.

What is claimed is:
 1. A method comprising: a) transmitting a pluralityof control format indicators by a base station, said base stationconfigured to communicate employing a plurality of carriers, a controlformat indicator in said plurality of control format indicators: i)transmitted on a first control channel over the first OFDM symbol in aplurality of OFDM symbols of a first subframe in a plurality ofsubframes, said plurality of control format indicators transmitted on afirst carrier in said plurality of carriers; and ii) indicating a numberof OFDM symbols in said first subframe employed for transmission ofdownlink control information on a second control channel on said firstsubframe of said first carrier; b) transmitting said downlink controlinformation by said base station on said first subframe of said firstcarrier, said downlink control information: i) transmitted on said firstcarrier starting from the first OFDM symbol of said first subframe; andii) providing first transmission format and scheduling information for afirst plurality of data packets to be transmitted on a first datachannel of said first carrier, transmission of said first plurality ofdata packets starting from an OFDM symbol subsequent to said number ofOFDM symbols employed for transmission of said downlink controlinformation; c) transmitting at least one control message by said basestation, said at least one control message configured to cause, in awireless device, configuration of radio resources of: i) a secondcontrol channel of a second carrier in said plurality of carriers, saidradio resources comprising one or more sets of resource blocks in asubset of subframes in said plurality of subframes, said at least onecontrol message indicating, for at least one of said one or more sets ofresource blocks: (1) a starting OFDM symbol in a second subframe of saidsubset of subframes; and (2) a frequency allocation in terms of resourceblocks in said second subframe; and ii) a second data channel of saidsecond carrier to start from said starting OFDM symbol of said secondsubframe; d) transmitting second transmission format and schedulinginformation by said base station on said second control channel in saidsecond subframe, said second transmission format and schedulinginformation being for one or more second data packets to be transmittedon said second data channel; and e) transmitting said one or more seconddata packets by said base station on said second data channel in saidsecond subframe.
 2. The method of claim 1, wherein said at least onecontrol message is transmitted on said first data channel.
 3. The methodof claim 1, wherein said one or more set of resource blocks in asubframe ends at the last symbol of said subframe.
 4. The method ofclaim 1, wherein the range of possible values of said control formatindicator depends on a bandwidth of said first carrier.
 5. The method ofclaim 1, wherein said control format indicator is scrambled by a cell IDbefore transmission.
 6. The method of claim 1, wherein said downlinkcontrol information is transmitted employing QPSK modulated symbols. 7.The method of claim 1, wherein said first plurality of data packets andsaid second plurality of data packets comprise encrypted data packets.8. The method of claim 1, wherein said first plurality of data packetsand said second plurality of data packets are assigned to a radiobearer.
 9. The method of claim 1, wherein at least one of said at leastone control message sets up or modifies at least one radio bearer. 10.The method of claim 1, further comprising said base station receivingfrom said wireless device, control data over a physical uplink controlchannel on a first uplink carrier, said first uplink carriercorresponding to said first carrier, said control data comprising: a)positive/negative acknowledgements for some of said first plurality ofdata packets and said second plurality of data packets; and b) channelstate information for said first carrier and said second carrier.
 11. Awireless device, configured to communicate employing a plurality ofcarriers, comprising: a) one or more communication interfaces; b) one ormore processors; and c) memory storing instructions that, when executed,cause said wireless device to: i) receive downlink control informationfrom a base station, said downlink control information: (1) received ona first carrier in said plurality of carriers starting from the firstOFDM symbol in a plurality of OFDM symbols of a first subframe in aplurality of subframes of a first carrier; and (2) providing firsttransmission format and scheduling information for one or more firstdata packets to be received on a first data channel of said firstcarrier; ii) receive at least one control message from said basestation, said at least one control message configured to causeconfiguration of radio resources of: (1) a second control channel of asecond carrier in said plurality of carriers, said radio resourcescomprising one or more sets of resource blocks in a subset of subframesin said plurality of subframes, said at least one control messageindicating, for at least one of said one or more sets of resourceblocks: (a) a starting OFDM symbol in a second subframe of said subsetof subframes; and (b) a frequency allocation in terms of resource blocksin said second subframe; and (2) a second data channel of said secondcarrier to start from said starting OFDM symbol; iii) receive secondtransmission format and scheduling information from said base station onsaid second control channel in said second subframe of said subset ofsubframes, said transmission format and scheduling information being forone or more second data packets to be received on said second datachannel of said second carrier; and iv) receive said one or more seconddata packets from said base station on said second data channel in saidsecond subframe employing said second transmission format and schedulinginformation.
 12. The wireless device of claim 11, wherein the range ofpossible values of said control format indicator depends on the firstcarrier bandwidth.
 13. The wireless device of claim 11, wherein saidsecond data channel of said second carrier ends at the last OFDM symbolof said second subframe.
 14. The wireless device of claim 11, wherein atleast one of said at least one control message is configured to causesaid wireless device to modify a configuration of at least one parameterof a media access control layer or a physical layer.
 15. A methodcomprising: a) transmitting downlink control information by a basestation, said base station configured to communicate employing aplurality of carriers, said downlink control information: i) transmittedon a first carrier in said plurality of carriers starting from the firstOFDM symbol in a plurality of OFDM symbols of a first subframe in aplurality of subframes of said first carrier; and ii) providing firsttransmission format and scheduling information for a first plurality ofdata packets to be transmitted on a first data channel of said firstcarrier; b) transmitting at least one control message by said basestation to a wireless device, said at least one control messageconfigured to cause, in said wireless device, configuration of radioresources of: i) a second control channel of a second carrier in saidplurality of carriers, said radio resources comprising one or more setsof resource blocks in a subset of subframes in said plurality ofsubframes, said at least one control message indicating, for at leastone of said one or more sets of resource blocks: (1) a starting OFDMsymbol in a second subframe of said subset of subframes; and (2) afrequency allocation in terms of resource blocks in said secondsubframe; and ii) a second data channel of said second carrier to startfrom said starting OFDM symbol; c) transmitting second transmissionformat and scheduling information by said base station on said secondcontrol channel in said second subframe of said subset of subframes,said transmission format and scheduling information being for one ormore second data packets to be transmitted on said second data channelof said second carrier; and d) transmitting said one or more second datapackets by said base station to said wireless device on said second datachannel in said second subframe employing said second transmissionformat and scheduling information.
 16. The method of claim 15, whereinsaid at least one control message is transmitted on said first datachannel.
 17. The method of claim 15, wherein said one or more sets ofresource blocks in a subframe ends at the last symbol of said subframe.18. The method of claim 15, wherein said at least one control messagefurther indicates said subset of subframes in which radio resources ofsaid second control channel are configured.
 19. The method of claim 15,further comprising transmitting third transmission format and schedulinginformation by said base station on said second control channel, saidthird transmission format and scheduling information being for one ormore third data packets to be received on a second uplink carriercorresponding to said second carrier.
 20. The method of claim 19,further comprising: a) receiving said one or more third data packets bysaid base station from said wireless device on said second uplinkcarrier employing said third transmission format and schedulinginformation; and b) transmitting a positive/negative acknowledgementsignal on a physical HARQ indicator channel (PHICH) on said secondcarrier, said positive/negative acknowledgement signal providing one ormore positive or negative acknowledgements to said wireless device forthe receipt of said one or more third data packets.